Multiplication and Division of Rational Expressions
Frank Ma © 2011
Multiplication Rule for Rational Expressions
A
B
C
D
* =
AC
BD
Multiplication and Division of Rational Expressions
Multiplication Rule for Rational Expressions
A
B
C
D
* =
AC
BD
Multiplication and Division of Rational Expressions
In most problems, we reduce the product by factoring the
top and the bottom, then cancel.
Multiplication Rule for Rational Expressions
A
B
C
D
* =
AC
BD
Multiplication and Division of Rational Expressions
In most problems, we reduce the product by factoring the
top and the bottom, then cancel.
Example A. Simplify
10x
y3z
a. *
y2
5x3
Multiplication Rule for Rational Expressions
A
B
C
D
* =
AC
BD
Multiplication and Division of Rational Expressions
In most problems, we reduce the product by factoring the
top and the bottom, then cancel.
Example A. Simplify
10x
y3z
a. *
y2
5x3 = 10xy2
5x3y3z
Multiplication Rule for Rational Expressions
A
B
C
D
* =
AC
BD
Multiplication and Division of Rational Expressions
In most problems, we reduce the product by factoring the
top and the bottom, then cancel.
Example A. Simplify
10x
y3z
a. *
y2
5x3 = 10xy2
5x3y3z = 2
x2yz
Multiplication Rule for Rational Expressions
A
B
C
D
* =
AC
BD
Multiplication and Division of Rational Expressions
In most problems, we reduce the product by factoring the
top and the bottom, then cancel.
Example A. Simplify
10x
y3z
a. *
y2
5x3 = 10xy2
5x3y3z = 2
x2yz
b.
(x2 + 2x – 3 )
(x – 2) (x2 – x )
(x2 – 4 )
*
Multiplication Rule for Rational Expressions
A
B
C
D
* =
AC
BD
Multiplication and Division of Rational Expressions
In most problems, we reduce the product by factoring the
top and the bottom, then cancel.
Example A. Simplify
10x
y3z
a. *
y2
5x3 = 10xy2
5x3y3z = 2
x2yz
b.
(x2 + 2x – 3 )
(x – 2) (x2 – x )
(x2 – 4 )
*
=
(x + 3)(x – 1 )
Multiplication Rule for Rational Expressions
A
B
C
D
* =
AC
BD
Multiplication and Division of Rational Expressions
In most problems, we reduce the product by factoring the
top and the bottom, then cancel.
Example A. Simplify
10x
y3z
a. *
y2
5x3 = 10xy2
5x3y3z = 2
x2yz
b.
(x2 + 2x – 3 )
(x – 2) (x2 – x )
(x2 – 4 )
*
=
(x + 3)(x – 1 ) (x + 2 )(x – 2)
Multiplication Rule for Rational Expressions
A
B
C
D
* =
AC
BD
Multiplication and Division of Rational Expressions
In most problems, we reduce the product by factoring the
top and the bottom, then cancel.
Example A. Simplify
10x
y3z
a. *
y2
5x3 = 10xy2
5x3y3z = 2
x2yz
b.
(x2 + 2x – 3 )
(x – 2) (x2 – x )
(x2 – 4 )
*
=
(x + 3)(x – 1 )
(x – 2)
(x + 2 )(x – 2)
Multiplication Rule for Rational Expressions
A
B
C
D
* =
AC
BD
Multiplication and Division of Rational Expressions
In most problems, we reduce the product by factoring the
top and the bottom, then cancel.
Example A. Simplify
10x
y3z
a. *
y2
5x3 = 10xy2
5x3y3z = 2
x2yz
b.
(x2 + 2x – 3 )
(x – 2) (x2 – x )
(x2 – 4 )
*
=
(x + 3)(x – 1 )
(x – 2) x(x – 1 )
(x + 2 )(x – 2)
Multiplication Rule for Rational Expressions
A
B
C
D
* =
AC
BD
Multiplication and Division of Rational Expressions
In most problems, we reduce the product by factoring the
top and the bottom, then cancel.
Example A. Simplify
10x
y3z
a. *
y2
5x3 = 10xy2
5x3y3z = 2
x2yz
b.
(x2 + 2x – 3 )
(x – 2) (x2 – x )
(x2 – 4 )
*
=
(x + 3)(x – 1 )
(x – 2) x(x – 1 )
(x + 2 )(x – 2)
Multiplication Rule for Rational Expressions
A
B
C
D
* =
AC
BD
Multiplication and Division of Rational Expressions
In most problems, we reduce the product by factoring the
top and the bottom, then cancel.
Example A. Simplify
10x
y3z
a. *
y2
5x3 = 10xy2
5x3y3z = 2
x2yz
b.
(x2 + 2x – 3 )
(x – 2) (x2 – x )
(x2 – 4 )
*
=
(x + 3)(x – 1 )
(x – 2) x(x – 1 )
(x + 2 )(x – 2)
Multiplication Rule for Rational Expressions
A
B
C
D
* =
AC
BD
Multiplication and Division of Rational Expressions
In most problems, we reduce the product by factoring the
top and the bottom, then cancel.
Example A. Simplify
10x
y3z
a. *
y2
5x3 = 10xy2
5x3y3z = 2
x2yz
b.
(x2 + 2x – 3 )
(x – 2) (x2 – x )
(x2 – 4 )
=
(x + 3)(x + 2)
x
*
=
(x + 3)(x – 1 )
(x – 2) x(x – 1 )
(x + 2 )(x – 2)
In the next section, we meet the following type of problems.
Multiplication and Division of Rational Expressions
Example B. Simplify and expand the answers.
a. x + 3
x – 1
(x2 – 1)
Multiplication and Division of Rational Expressions
a. x + 3
x – 1
(x2 – 1)
= x + 3
(x – 1) (x – 1)(x + 1)
Example B. Simplify and expand the answers.
Multiplication and Division of Rational Expressions
Example B. Simplify and expand the answers.
a. x + 3
x – 1
(x2 – 1)
= x + 3
(x – 1) (x – 1)(x + 1)
= (x + 3)(x + 1)
Multiplication and Division of Rational Expressions
a. x + 3
x – 1
(x2 – 1)
= x + 3
(x – 1) (x – 1)(x + 1)
= (x + 3)(x + 1) = x2 + 4x + 3
Example B. Simplify and expand the answers.
Multiplication and Division of Rational Expressions
a. x + 3
x – 1
(x2 – 1)
= x + 3
(x – 1) (x – 1)(x + 1)
= (x + 3)(x + 1) = x2 + 4x + 3
b. x – 2
x2 – 9
( –
x + 1
x2 – 2x – 3
) ( x – 3)(x + 3)(x + 1)
Example B. Simplify and expand the answers.
Multiplication and Division of Rational Expressions
a. x + 3
x – 1
(x2 – 1)
= x + 3
(x – 1) (x – 1)(x + 1)
= (x + 3)(x + 1) = x2 + 4x + 3
b. x – 2
x2 – 9
( –
x + 1
x2 – 2x – 3
) ( x – 3)(x + 3)(x + 1)
=
x – 2
(x – 3)(x + 3)
Example B. Simplify and expand the answers.
Multiplication and Division of Rational Expressions
a. x + 3
x – 1
(x2 – 1)
= x + 3
(x – 1) (x – 1)(x + 1)
= (x + 3)(x + 1) = x2 + 4x + 3
b. x – 2
x2 – 9
( –
x + 1
x2 – 2x – 3
) ( x – 3)(x + 3)(x + 1)
=
x – 2
(x – 3)(x + 3)
–
x + 1
(x – 3)(x + 1)
Example B. Simplify and expand the answers.
Multiplication and Division of Rational Expressions
a. x + 3
x – 1
(x2 – 1)
= x + 3
(x – 1) (x – 1)(x + 1)
= (x + 3)(x + 1) = x2 + 4x + 3
b. x – 2
x2 – 9
( –
x + 1
x2 – 2x – 3
) ( x – 3)(x + 3)(x + 1)
=
x – 2
(x – 3)(x + 3)
[ –
x + 1
(x – 3)(x + 1)
] ( x – 3)(x + 3)(x + 1)
Example B. Simplify and expand the answers.
Multiplication and Division of Rational Expressions
a. x + 3
x – 1
(x2 – 1)
= x + 3
(x – 1) (x – 1)(x + 1)
= (x + 3)(x + 1) = x2 + 4x + 3
b. x – 2
x2 – 9
( –
x + 1
x2 – 2x – 3
) ( x – 3)(x + 3)(x + 1)
=
x – 2
(x – 3)(x + 3)
[ –
x + 1
(x – 3)(x + 1)
] ( x – 3)(x + 3)(x + 1)
(x + 1)
Example B. Simplify and expand the answers.
Multiplication and Division of Rational Expressions
a. x + 3
x – 1
(x2 – 1)
= x + 3
(x – 1) (x – 1)(x + 1)
= (x + 3)(x + 1) = x2 + 4x + 3
b. x – 2
x2 – 9
( –
x + 1
x2 – 2x – 3
) ( x – 3)(x + 3)(x + 1)
=
x – 2
(x – 3)(x + 3)
[ –
x + 1
(x – 3)(x + 1)
] ( x – 3)(x + 3)(x + 1)
(x + 1) (x + 3)
Example B. Simplify and expand the answers.
Multiplication and Division of Rational Expressions
a. x + 3
x – 1
(x2 – 1)
= x + 3
(x – 1) (x – 1)(x + 1)
= (x + 3)(x + 1) = x2 + 4x + 3
b. x – 2
x2 – 9
( –
x + 1
x2 – 2x – 3
) ( x – 3)(x + 3)(x + 1)
=
x – 2
(x – 3)(x + 3)
[ –
x + 1
(x – 3)(x + 1)
] ( x – 3)(x + 3)(x + 1)
(x + 1) (x + 3)
= (x – 2)(x + 1) – (x + 1)(x + 3)
Example B. Simplify and expand the answers.
Multiplication and Division of Rational Expressions
a. x + 3
x – 1
(x2 – 1)
= x + 3
(x – 1) (x – 1)(x + 1)
= (x + 3)(x + 1) = x2 + 4x + 3
b. x – 2
x2 – 9
( –
x + 1
x2 – 2x – 3
) ( x – 3)(x + 3)(x + 1)
=
x – 2
(x – 3)(x + 3)
[ –
x + 1
(x – 3)(x + 1)
] ( x – 3)(x + 3)(x + 1)
(x + 1) (x + 3)
= (x – 2)(x + 1) – (x + 1)(x + 3)
= (x – 2)(x + 1) + (–x –1)(x + 3)
Example B. Simplify and expand the answers.
Multiplication and Division of Rational Expressions
a. x + 3
x – 1
(x2 – 1)
= x + 3
(x – 1) (x – 1)(x + 1)
= (x + 3)(x + 1) = x2 + 4x + 3
b. x – 2
x2 – 9
( –
x + 1
x2 – 2x – 3
) ( x – 3)(x + 3)(x + 1)
=
x – 2
(x – 3)(x + 3)
[ –
x + 1
(x – 3)(x + 1)
] ( x – 3)(x + 3)(x + 1)
(x + 1) (x + 3)
= (x – 2)(x + 1) – (x + 1)(x + 3)
= (x – 2)(x + 1) + (–x –1)(x + 3)
= x2 – x – 2 – x2 – 4x – 3
Example B. Simplify and expand the answers.
Multiplication and Division of Rational Expressions
Example B. Simplify and expand the answers.
a. x + 3
x – 1
(x2 – 1)
= x + 3
(x – 1) (x – 1)(x + 1)
= (x + 3)(x + 1) = x2 + 4x + 3
b. x – 2
x2 – 9
( –
x + 1
x2 – 2x – 3
) ( x – 3)(x + 3)(x + 1)
=
x – 2
(x – 3)(x + 3)
[ –
x + 1
(x – 3)(x + 1)
] ( x – 3)(x + 3)(x + 1)
(x + 1) (x + 3)
= (x – 2)(x + 1) – (x + 1)(x + 3)
= (x – 2)(x + 1) + (–x –1)(x + 3)
= x2 – x – 2 – x2 – 4x – 3
= –5x – 5
Division Rule for Rational Expressions
Multiplication and Division of Rational Expressions
A
B
C
D
÷
Division Rule for Rational Expressions
Multiplication and Division of Rational Expressions
A
B
C
D
÷ =
AD
BC
Reciprocate
Division Rule for Rational Expressions
Multiplication and Division of Rational Expressions
A
B
C
D
÷ =
AD
BC
Reciprocate
We convert division by an expression of multiplying by its
reciprocal.
Division Rule for Rational Expressions
Multiplication and Division of Rational Expressions
A
B
C
D
÷ =
AD
BC
Reciprocate
We convert division by an expression of multiplying by its
reciprocal. Then we factor and reduce the product.
Division Rule for Rational Expressions
Multiplication and Division of Rational Expressions
A
B
C
D
÷ =
AD
BC
Reciprocate
(2x – 6)
(x + 3)
÷
(x2 + 2x – 3)
(9 – x2)
Example C. Simplify
We convert division by an expression of multiplying by its
reciprocal. Then we factor and reduce the product.
Division Rule for Rational Expressions
Multiplication and Division of Rational Expressions
A
B
C
D
÷ =
AD
BC
Reciprocate
(2x – 6)
(x + 3)
÷
(x2 + 2x – 3)
(9 – x2)
=
(2x – 6)
(x + 3)
(x2 + 2x – 3)
(9 – x2)
*
Example C. Simplify
We convert division by an expression of multiplying by its
reciprocal. Then we factor and reduce the product.
Division Rule for Rational Expressions
Multiplication and Division of Rational Expressions
A
B
C
D
÷ =
AD
BC
Reciprocate
(2x – 6)
(x + 3)
÷
(x2 + 2x – 3)
(9 – x2)
=
(2x – 6)
(x + 3)
(x2 + 2x – 3)
(9 – x2)
*
=
2(x – 3)
(x + 3)
Example C. Simplify
We convert division by an expression of multiplying by its
reciprocal. Then we factor and reduce the product.
Division Rule for Rational Expressions
Multiplication and Division of Rational Expressions
A
B
C
D
÷ =
AD
BC
Reciprocate
(2x – 6)
(x + 3)
÷
(x2 + 2x – 3)
(9 – x2)
=
(2x – 6)
(x + 3)
(x2 + 2x – 3)
(9 – x2)
*
=
2(x – 3)
(x + 3)
(x + 3)(x – 1)
(3 – x)(3 + x)
Example C. Simplify
We convert division by an expression of multiplying by its
reciprocal. Then we factor and reduce the product.
Division Rule for Rational Expressions
Multiplication and Division of Rational Expressions
A
B
C
D
÷ =
AD
BC
Reciprocate
Example C. Simplify
(2x – 6)
(x + 3)
÷
(x2 + 2x – 3)
(9 – x2)
=
(2x – 6)
(x + 3)
(x2 + 2x – 3)
(9 – x2)
*
=
2(x – 3)
(x + 3)
(x + 3)(x – 1)
(3 – x)(3 + x)
*
(9 – x2)
We convert division by an expression of multiplying by its
reciprocal. Then we factor and reduce the product.
Division Rule for Rational Expressions
Multiplication and Division of Rational Expressions
A
B
C
D
÷ =
AD
BC
Reciprocate
(2x – 6)
(x + 3)
÷
(x2 + 2x – 3)
(9 – x2)
=
(2x – 6)
(x + 3)
(x2 + 2x – 3)
(9 – x2)
*
=
2(x – 3)
(x + 3)
(x + 3)(x – 1)
(3 – x)(3 + x)
*
(–1)
Example C. Simplify
We convert division by an expression of multiplying by its
reciprocal. Then we factor and reduce the product.
Division Rule for Rational Expressions
Multiplication and Division of Rational Expressions
A
B
C
D
÷ =
AD
BC
Reciprocate
(2x – 6)
(x + 3)
÷
(x2 + 2x – 3)
(9 – x2)
=
(2x – 6)
(x + 3)
(x2 + 2x – 3)
(9 – x2)
*
=
2(x – 3)
(x + 3)
(x + 3)(x – 1)
(3 – x)(3 + x)
*
(–1)
=
–2(x – 1)
(3 + x)
Example C. Simplify
We convert division by an expression of multiplying by its
reciprocal. Then we factor and reduce the product.
Multiplication and Division of Rational Expressions
Besides the expanded form and factored forms, rational
expressions may also be split into sums or differences.
Multiplication and Division of Rational Expressions
Besides the expanded form and factored forms, rational
expressions may also be split into sums or differences.
There are two common ways to do this.
Multiplication and Division of Rational Expressions
Besides the expanded form and factored forms, rational
expressions may also be split into sums or differences.
There are two common ways to do this.
I. Split off the numerator term by term.
Multiplication and Division of Rational Expressions
Example D. Break up the numerators as the sums or
differences and simplify each term.
(2x – 6)
(x + 3)
a. =
Besides the expanded form and factored forms, rational
expressions may also be split into sums or differences.
There are two common ways to do this.
I. Split off the numerator term by term.
(2x – 6)
3x2
b. =
Multiplication and Division of Rational Expressions
Example D. Break up the numerators as the sums or
differences and simplify each term.
(2x – 6)
(x + 3)
a. =
Besides the expanded form and factored forms, rational
expressions may also be split into sums or differences.
There are two common ways to do this.
I. Split off the numerator term by term.
(x + 3) – (x + 3)
2x 6
(2x – 6)
3x2
b. =
Multiplication and Division of Rational Expressions
Example D. Break up the numerators as the sums or
differences and simplify each term.
(2x – 6)
(x + 3)
a. =
Besides the expanded form and factored forms, rational
expressions may also be split into sums or differences.
There are two common ways to do this.
I. Split off the numerator term by term.
(x + 3) – (x + 3)
2x 6
(2x – 6)
3x2
b. = –
2x 6
3x2 3x2
Multiplication and Division of Rational Expressions
Example D. Break up the numerators as the sums or
differences and simplify each term.
(2x – 6)
(x + 3)
a. =
Besides the expanded form and factored forms, rational
expressions may also be split into sums or differences.
There are two common ways to do this.
I. Split off the numerator term by term.
(x + 3) – (x + 3)
2x 6
(2x – 6)
3x2
b. = –
2x 6
3x2 3x2 = –
2
x2
2
3x
Multiplication and Division of Rational Expressions
Example D. Break up the numerators as the sums or
differences and simplify each term.
(2x – 6)
(x + 3)
a. =
Besides the expanded form and factored forms, rational
expressions may also be split into sums or differences.
There are two common ways to do this.
I. Split off the numerator term by term.
(x + 3) – (x + 3)
2x 6
(2x – 6)
3x2
b. = –
2x 6
3x2 3x2 = –
2
x2
2
3x
II. Long Division
Long division is the extension of the long division of numbers
from grade school and it is for the division of polynomials in
one variable.
Multiplication and Division of Rational Expressions
Example D. Break up the numerators as the sums or
differences and simplify each term.
(2x – 6)
(x + 3)
a. =
Besides the expanded form and factored forms, rational
expressions may also be split into sums or differences.
There are two common ways to do this.
I. Split off the numerator term by term.
(x + 3) – (x + 3)
2x 6
(2x – 6)
3x2
b. = –
2x 6
3x2 3x2 = –
2
x2
2
3x
II. Long Division
Long division is the extension of the long division of numbers
from grade school and it is for the division of polynomials in
one variable. Specifically, long division gives relevant results
only when the degree of the numerator is the same or more
than the degree of the denominator.
Multiplication and Division of Rational Expressions
Let’s look at the example 125/8 or 125 ÷ 8 by long division.
Multiplication and Division of Rational Expressions
Let’s look at the example 125/8 or 125 ÷ 8 by long division.
i. Put the problem in the long division
format with the “bottom-out” and
move from left to right until there is
enough to enter a quotient.
Multiplication and Division of Rational Expressions
Let’s look at the example 125/8 or 125 ÷ 8 by long division.
i. Put the problem in the long division
format with the “bottom-out” and
move from left to right until there is
enough to enter a quotient. )8 125
Multiplication and Division of Rational Expressions
Let’s look at the example 125/8 or 125 ÷ 8 by long division.
i. Put the problem in the long division
format with the “bottom-out” and
move from left to right until there is
enough to enter a quotient. )8 125
1
Multiplication and Division of Rational Expressions
Let’s look at the example 125/8 or 125 ÷ 8 by long division.
i. Put the problem in the long division
format with the “bottom-out” and
move from left to right until there is
enough to enter a quotient. )8 125
1
ii. Multiply the quotient back into the
problem and subtract the results from
the numerator. Bring down the
remaining terms from the numerator.
8
45
Multiplication and Division of Rational Expressions
Let’s look at the example 125/8 or 125 ÷ 8 by long division.
i. Put the problem in the long division
format with the “bottom-out” and
move from left to right until there is
enough to enter a quotient. )8 125
1
ii. Multiply the quotient back into the
problem and subtract the results from
the numerator. Bring down the
remaining terms from the numerator.
8
45
iii. Repeat steps i and ii until no more
quotient may be entered.
Multiplication and Division of Rational Expressions
i. Put the problem in the long division
format with the “bottom-out” and
move from left to right until there is
enough to enter a quotient. )8 125
15
ii. Multiply the quotient back into the
problem and subtract the results from
the numerator. Bring down the
remaining terms from the numerator.
8
45
iii. Repeat steps i and ii until no more
quotient may be entered.
40
5
Let’s look at the example 125/8 or 125 ÷ 8 by long division.
Multiplication and Division of Rational Expressions
i. Put the problem in the long division
format with the “bottom-out” and
move from left to right until there is
enough to enter a quotient. )8 125
15
ii. Multiply the quotient back into the
problem and subtract the results from
the numerator. Bring down the
remaining terms from the numerator.
8
45
iii. Repeat steps i and ii until no more
quotient may be entered. Then we may
put the fraction N/D in the following
mixed form:
N
D
= Q + R
D
and that R (the remainder) is smaller then D (no more quotient).
40
5
where Q is the quotient
Let’s look at the example 125/8 or 125 ÷ 8 by long division.
Multiplication and Division of Rational Expressions
i. Put the problem in the long division
format with the “bottom-out” and
move from left to right until there is
enough to enter a quotient. )8 125
15
ii. Multiply the quotient back into the
problem and subtract the results from
the numerator. Bring down the
remaining terms from the numerator.
8
45
iii. Repeat steps i and ii until no more
quotient may be entered. Then we may
put the fraction N/D in the following
mixed form:
N
D
= Q + R
D
and that R (the remainder) is smaller then D (no more quotient).
40
5
125
8
= 15 + 5
8
where Q is the quotient
Let’s look at the example 125/8 or 125 ÷ 8 by long division.
Multiplication and Division of Rational Expressions
Example E. Divide using long division(2x – 6)
(x + 3)
Multiplication and Division of Rational Expressions
i. Put the problem in the long division
format with the “bottom-out” and
enter the quotients of the leading
terms.
Example E. Divide using long division(2x – 6)
(x + 3)
Multiplication and Division of Rational Expressions
)x + 3 2x – 6
i. Put the problem in the long division
format with the “bottom-out” and
enter the quotients of the leading
terms.
Make sure the terms
are in order.
Example E. Divide using long division(2x – 6)
(x + 3)
Multiplication and Division of Rational Expressions
)x + 3 2x – 6
i. Put the problem in the long division
format with the “bottom-out” and
enter the quotients of the leading
terms.
Make sure the terms
are in order.
Example E. Divide using long division(2x – 6)
(x + 3)
Multiplication and Division of Rational Expressions
)x + 3 2x – 6
i. Put the problem in the long division
format with the “bottom-out” and
enter the quotients of the leading
terms.
enter the quotients of the
leading terms 2x/x = 2
Example E. Divide using long division(2x – 6)
(x + 3)
Multiplication and Division of Rational Expressions
)x + 3 2x – 6
2
i. Put the problem in the long division
format with the “bottom-out” and
enter the quotients of the leading
terms.
enter the quotients of the
leading terms 2x/x = 2
Example E. Divide using long division(2x – 6)
(x + 3)
Multiplication and Division of Rational Expressions
)x + 3 2x – 6
2
ii. Multiply the quotient back into the
problem and subtract the results from
the numerator. Bring down the
remaining terms from the numerator.
i. Put the problem in the long division
format with the “bottom-out” and
enter the quotients of the leading
terms.
Example E. Divide using long division(2x – 6)
(x + 3)
Multiplication and Division of Rational Expressions
)x + 3 2x – 6
2
2x + 6
ii. Multiply the quotient back into the
problem and subtract the results from
the numerator. Bring down the
remaining terms from the numerator.
i. Put the problem in the long division
format with the “bottom-out” and
enter the quotients of the leading
terms.
Example E. Divide using long division(2x – 6)
(x + 3)
Multiplication and Division of Rational Expressions
)x + 3 2x – 6
2
ii. Multiply the quotient back into the
problem and subtract the results from
the numerator. Bring down the
remaining terms from the numerator.
2x + 6
–12
–)
i. Put the problem in the long division
format with the “bottom-out” and
enter the quotients of the leading
terms.
Example E. Divide using long division(2x – 6)
(x + 3)
Multiplication and Division of Rational Expressions
)x + 3 2x – 6
2
ii. Multiply the quotient back into the
problem and subtract the results from
the numerator. Bring down the
remaining terms from the numerator.
2x + 6
–12
iii. Repeat steps i and ii until no more
quotient may be entered.
–)
i. Put the problem in the long division
format with the “bottom-out” and
enter the quotients of the leading
terms.
Example E. Divide using long division(2x – 6)
(x + 3)
Multiplication and Division of Rational Expressions
)x + 3 2x – 6
2
ii. Multiply the quotient back into the
problem and subtract the results from
the numerator. Bring down the
remaining terms from the numerator.
2x + 6
–12
–)
Stop. No more
quotient since
x can’t going into 12.
iii. Repeat steps i and ii until no more
quotient may be entered.
i. Put the problem in the long division
format with the “bottom-out” and
enter the quotients of the leading
terms.
Example E. Divide using long division(2x – 6)
(x + 3)
Multiplication and Division of Rational Expressions
)x + 3 2x – 6
2
ii. Multiply the quotient back into the
problem and subtract the results from
the numerator. Bring down the
remaining terms from the numerator.
2x + 6
–12
iii. Repeat steps i and ii until no more
quotient may be entered. Then we may
put the fraction N/D in the following
mixed form:
–)
N
D
= Q + R
D
has smaller degree then denominator D (no more quotient).
where Q is the quotient and the remainder R
i. Put the problem in the long division
format with the “bottom-out” and
enter the quotients of the leading
terms.
Example E. Divide using long division(2x – 6)
(x + 3)
Multiplication and Division of Rational Expressions
)x + 3 2x – 6
2
ii. Multiply the quotient back into the
problem and subtract the results from
the numerator. Bring down the
remaining terms from the numerator.
2x + 6
–12
iii. Repeat steps i and ii until no more
quotient may be entered. Then we may
put the fraction N/D in the following
mixed form:
–)
Hence we may write
(2x – 6)
(x + 3)
N
D
= Q + R
D
has smaller degree then denominator D (no more quotient).
where Q is the quotient and the remainder R
i. Put the problem in the long division
format with the “bottom-out” and
enter the quotients of the leading
terms.
Example E. Divide using long division(2x – 6)
(x + 3)
Multiplication and Division of Rational Expressions
)x + 3 2x – 6
2
ii. Multiply the quotient back into the
problem and subtract the results from
the numerator. Bring down the
remaining terms from the numerator.
2x + 6
–12
iii. Repeat steps i and ii until no more
quotient may be entered. Then we may
put the fraction N/D in the following
mixed form:
–)
Hence we may write
(2x – 6)
(x + 3)
N
D
= Q + R
D
has smaller degree then denominator D (no more quotient).
where Q is the quotient and the remainder R
i. Put the problem in the long division
format with the “bottom-out” and
enter the quotients of the leading
terms.
Q
R
Example E. Divide using long division(2x – 6)
(x + 3)
Multiplication and Division of Rational Expressions
)x + 3 2x – 6
2
ii. Multiply the quotient back into the
problem and subtract the results from
the numerator. Bring down the
remaining terms from the numerator.
2x + 6
–12
iii. Repeat steps i and ii until no more
quotient may be entered. Then we may
put the fraction N/D in the following
mixed form:
= 2 – 12
x + 3
–)
Hence we may write
(2x – 6)
(x + 3)
N
D
= Q + R
D
has smaller degree then denominator D (no more quotient).
where Q is the quotient and the remainder R
i. Put the problem in the long division
format with the “bottom-out” and
enter the quotients of the leading
terms.
Q
R
Q R
Example E. Divide using long division(2x – 6)
(x + 3)
Multiplication and Division of Rational Expressions
Example F. Divide using long division
ii. Multiply the quotient back into the
problem and subtract the results from
the numerator. Bring down the
remaining terms from the numerator.
iii. Repeat steps i and ii until no more
quotient may be entered. Then we may
put the fraction N/D in the following
mixed form:
x2 – 6x + 3
x – 2
N
D
= Q + R
D
has smaller degree then denominator D (no more quotient).
where Q is the quotient and the remainder R
i. Put the problem in the long division
format with the “bottom-out” and
enter the quotients of the leading
terms.
Multiplication and Division of Rational Expressions
)x + 3
ii. Multiply the quotient back into the
problem and subtract the results from
the numerator. Bring down the
remaining terms from the numerator.
iii. Repeat steps i and ii until no more
quotient may be entered. Then we may
put the fraction N/D in the following
mixed form:
x2 – 6x + 3
Make sure the terms
are in order.
N
D
= Q + R
D
has smaller degree then denominator D (no more quotient).
where Q is the quotient and the remainder R
i. Put the problem in the long division
format with the “bottom-out” and
enter the quotients of the leading
terms.
Example F. Divide using long divisionx2 – 6x + 3
x – 2
Multiplication and Division of Rational Expressions
)x + 3
ii. Multiply the quotient back into the
problem and subtract the results from
the numerator. Bring down the
remaining terms from the numerator.
iii. Repeat steps i and ii until no more
quotient may be entered. Then we may
put the fraction N/D in the following
mixed form:
x2 – 6x + 3
N
D
= Q + R
D
has smaller degree then denominator D (no more quotient).
where Q is the quotient and the remainder R
i. Put the problem in the long division
format with the “bottom-out” and
enter the quotients of the leading
terms.
Example F. Divide using long divisionx2 – 6x + 3
x – 2
Multiplication and Division of Rational Expressions
)x + 3
x
ii. Multiply the quotient back into the
problem and subtract the results from
the numerator. Bring down the
remaining terms from the numerator.
iii. Repeat steps i and ii until no more
quotient may be entered. Then we may
put the fraction N/D in the following
mixed form:
x2 – 6x + 3
N
D
= Q + R
D
has smaller degree then denominator D (no more quotient).
where Q is the quotient and the remainder R
i. Put the problem in the long division
format with the “bottom-out” and
enter the quotients of the leading
terms.
Example F. Divide using long divisionx2 – 6x + 3
x – 2
Multiplication and Division of Rational Expressions
)x + 3
x
ii. Multiply the quotient back into the
problem and subtract the results from
the numerator. Bring down the
remaining terms from the numerator.
x2 + 3x
iii. Repeat steps i and ii until no more
quotient may be entered. Then we may
put the fraction N/D in the following
mixed form:
x2 – 6x + 3
N
D
= Q + R
D
has smaller degree then denominator D (no more quotient).
where Q is the quotient and the remainder R
i. Put the problem in the long division
format with the “bottom-out” and
enter the quotients of the leading
terms.
Example F. Divide using long divisionx2 – 6x + 3
x – 2
Multiplication and Division of Rational Expressions
)x + 3
x
ii. Multiply the quotient back into the
problem and subtract the results from
the numerator. Bring down the
remaining terms from the numerator.
x2 + 3x
–9x + 3
iii. Repeat steps i and ii until no more
quotient may be entered. Then we may
put the fraction N/D in the following
mixed form:
–)
x2 – 6x + 3
N
D
= Q + R
D
has smaller degree then denominator D (no more quotient).
where Q is the quotient and the remainder R
i. Put the problem in the long division
format with the “bottom-out” and
enter the quotients of the leading
terms.
Example F. Divide using long divisionx2 – 6x + 3
x – 2
Multiplication and Division of Rational Expressions
)x + 3
x – 9
ii. Multiply the quotient back into the
problem and subtract the results from
the numerator. Bring down the
remaining terms from the numerator.
x2 + 3x
–9x + 3
iii. Repeat steps i and ii until no more
quotient may be entered. Then we may
put the fraction N/D in the following
mixed form:
–)
x2 – 6x + 3
N
D
= Q + R
D
has smaller degree then denominator D (no more quotient).
where Q is the quotient and the remainder R
i. Put the problem in the long division
format with the “bottom-out” and
enter the quotients of the leading
terms.
Example F. Divide using long divisionx2 – 6x + 3
x – 2
Multiplication and Division of Rational Expressions
)x + 3
x – 9
ii. Multiply the quotient back into the
problem and subtract the results from
the numerator. Bring down the
remaining terms from the numerator.
x2 + 3x
–9x + 3
iii. Repeat steps i and ii until no more
quotient may be entered. Then we may
put the fraction N/D in the following
mixed form:
–)
x2 – 6x + 3
–9x – 27
N
D
= Q + R
D
has smaller degree then denominator D (no more quotient).
where Q is the quotient and the remainder R
i. Put the problem in the long division
format with the “bottom-out” and
enter the quotients of the leading
terms.
Example F. Divide using long divisionx2 – 6x + 3
x – 2
Multiplication and Division of Rational Expressions
)x + 3
x – 9
ii. Multiply the quotient back into the
problem and subtract the results from
the numerator. Bring down the
remaining terms from the numerator.
x2 + 3x
–9x + 3
iii. Repeat steps i and ii until no more
quotient may be entered. Then we may
put the fraction N/D in the following
mixed form:
–)
x2 – 6x + 3
–9x – 27–)
30
N
D
= Q + R
D
has smaller degree then denominator D (no more quotient).
where Q is the quotient and the remainder R
i. Put the problem in the long division
format with the “bottom-out” and
enter the quotients of the leading
terms.
Example F. Divide using long divisionx2 – 6x + 3
x – 2
Multiplication and Division of Rational Expressions
)x + 3
x – 9
ii. Multiply the quotient back into the
problem and subtract the results from
the numerator. Bring down the
remaining terms from the numerator.
x2 + 3x
–9x + 3
iii. Repeat steps i and ii until no more
quotient may be entered. Then we may
put the fraction N/D in the following
mixed form:
N
D
= Q + R
D
has smaller degree then denominator D (no more quotient).
where Q is the quotient
–)
x2 – 6x + 3
–9x – 27–)
30
Stop. No more quotient
since x can’t going into
30. Hence 30 is the
remainder.
and the remainder R
i. Put the problem in the long division
format with the “bottom-out” and
enter the quotients of the leading
terms.
Example F. Divide using long divisionx2 – 6x + 3
x – 2
Multiplication and Division of Rational Expressions
)x + 3
x – 9
ii. Multiply the quotient back into the
problem and subtract the results from
the numerator. Bring down the
remaining terms from the numerator.
x2 + 3x
–9x + 3
iii. Repeat steps i and ii until no more
quotient may be entered. Then we may
put the fraction N/D in the following
mixed form:
–)
x2 – 6x + 3
–9x – 27–)
30
Hence
x2 – 6x + 3
x – 2
=
N
D
= Q + R
D
has smaller degree then denominator D (no more quotient).
where Q is the quotient and the remainder R
i. Put the problem in the long division
format with the “bottom-out” and
enter the quotients of the leading
terms.
Example F. Divide using long divisionx2 – 6x + 3
x – 2
Multiplication and Division of Rational Expressions
)x + 3
x – 9
ii. Multiply the quotient back into the
problem and subtract the results from
the numerator. Bring down the
remaining terms from the numerator.
x2 + 3x
–9x + 3
iii. Repeat steps i and ii until no more
quotient may be entered. Then we may
put the fraction N/D in the following
mixed form:
–)
x2 – 6x + 3
–9x – 27–)
30
Hence
x2 – 6x + 3
x – 2
= x – 9 + 30
x + 3
i. Put the problem in the long division
format with the “bottom-out” and
enter the quotients of the leading
terms.
N
D
= Q + R
D
has smaller degree then denominator D (no more quotient).
where Q is the quotient and the remainder R
Example F. Divide using long divisionx2 – 6x + 3
x – 2
Ex A. Simplify. Do not expand the results.
Multiplication and Division of Rational Expressions
1. 10x *
2
5x3
15x
4
*
16
25x4
10x
*
35x32.
5. 10
9x4
*
18
5x3
6.
3.12x6*
5
6x14
56x6
27
*
63
8x5
10x
*
35x34.
7. 75x
49
*
42
25x3
8.
9.
2x – 4
2x + 4
5x + 10
3x – 6
10.
6 – 4x
3x – 2
x – 2
2x + 4
11.
9x – 12
2x – 4
2 – x
8 – 6x
12.
x + 4
–x – 4
4 – x
x – 4
13.
3x – 9
15x – 5
3 – x
5 – 15x
14.
42 – 6x
–2x + 14
4 – 2x
–7x + 14
*
*
*
*
*
*
15.
(x2 + x – 2 )
(x – 2) (x2 – x)
(x2 – 4 )
*
16.
(x2 + 2x – 3 )
(x2 – 9) (x2 – x – 2 )
(x2 – 2x – 3)
*
17.
(x2 – x – 2 )
(x2 – 1) (x2 + 2x + 1)
(x2 + x )
*
18.
(x2 + 5x – 6 )
(x2 + 5x + 6) (x2 – 5x – 6 )
(x2 – 5x + 6)
*
19.
(x2 – 3x – 4 )
(x2 – 1) (x2 – 2x – 8)
(x2 – 3x + 2)
*
20.
(– x2 + 6 – x )
(x2 + 5x + 6) (x2 – x – 12 )
(6 – x2 – x)
*
Ex. A. Simplify. Do not expand the results.
Multiplication and Division of Rational Expressions
21.
(2x2 + x – 1 )
(1 – 2x)
(4x2 – 1)
(2x2 – x )
22.
(3x2 – 2x – 1)
(1 – 9x2)
(x2 + x – 2 )
(x2 + 4x + 4)
23.(3x2 – x – 2)
(x2 – x + 2) (3x2 + 4x + 1)
(–x – 3x2)
24.
(x + 1 – 6x2)
(–x2 – 4)
(2x2 + x – 1 )
(x2 – 5x – 6)
25. (x3 – 4x)
(–x2 + 4x – 4)
(x2 + 2)
(–x + 2)
26.
(–x3 + 9x ) (x2 + 6x + 9)
(x2 + 3x) (–3x2 – 9x)
Ex. B. Multiply, expand and simplify the results.
÷
÷
÷
÷
÷
÷
27. x + 3
x + 1
(x2 – 1) 28. x – 3
x – 2
(x2 – 4) 29. 2x + 3
1 – x
(x2 – 1)
30. 3 – 2x
x + 2 (x + 2)(x +1) 31. 3 – 2x
2x – 1 (3x + 2)(1 – 2x)
32. x – 2
x – 3
( +
x + 1
x + 3
)( x – 3)(x + 3)
33. 2x – 1
x + 2
( –
x + 2
2x – 3
) ( 2x – 3)(x + 2)
Multiplication and Division of Rational Expressions
38. x – 2
x2 – 9
( –
x + 1
x2 – 2x – 3
) ( x – 3)(x + 3)(x + 1)
39. x + 3
x2 – 4
( –
2x + 1
x2 + x – 2
) ( x – 2)(x + 2)(x – 1)
40. x – 1
x2 – x – 6
( –
x + 1
x2 – 2x – 3
) ( x – 3)(x + 2)(x + 1)
41. x + 2
x2 – 4x +3
( –
2x + 1
x2 + 2x – 3
)( x – 3)(x + 3)(x – 1)
34. 4 – x
x – 3
( –
x – 1
2x + 3
)( x – 3)(2x + 3)
35. 3 – x
x + 2
( – 2x + 3
x – 3
)(x – 3)(x + 2)
Ex B. Multiply, expand and simplify the results.
36. 3 – 4x
x + 1
( –
1 – 2x
x + 3
)( x + 3)(x + 1)
37. 5x – 7
x + 5
( –
4 – 5x
x – 3
)(x – 3)(x + 5)
Ex. C. Break up the following expressions as sums and
differences of fractions.
42.
43. 44.
45. 46. 47.
x2 + 4x – 6
2x2x2 – 4
x2
12x3 – 9x2 + 6x
3x
x2 – 4
2x
x
x8 – x6 – x4
x2
x8 – x6 – x4
Ex D. Use long division and write each rational expression in
the form of Q + .
R
D
(x2 + x – 2 )
(x – 1)
(3x2 – 3x – 2 )
(x + 2)
2x + 6
x + 2
48.
3x – 5
x – 2
49.
4x + 3
x – 1
50.
5x – 4
x – 3
51.
3x + 8
2 – x
52.
–4x – 5
1 – x
53.
54. (2x2 + x – 3 )
(x – 2)
55. 56.
(–x2 + 4x – 3 )
(x – 3)
(5x2 – 1 )
(x – 4)
57. (4x2 + 2 )
(x + 3)
58. 59.
Multiplication and Division of Rational Expressions

53 multiplication and division of rational expressions

  • 1.
    Multiplication and Divisionof Rational Expressions Frank Ma © 2011
  • 2.
    Multiplication Rule forRational Expressions A B C D * = AC BD Multiplication and Division of Rational Expressions
  • 3.
    Multiplication Rule forRational Expressions A B C D * = AC BD Multiplication and Division of Rational Expressions In most problems, we reduce the product by factoring the top and the bottom, then cancel.
  • 4.
    Multiplication Rule forRational Expressions A B C D * = AC BD Multiplication and Division of Rational Expressions In most problems, we reduce the product by factoring the top and the bottom, then cancel. Example A. Simplify 10x y3z a. * y2 5x3
  • 5.
    Multiplication Rule forRational Expressions A B C D * = AC BD Multiplication and Division of Rational Expressions In most problems, we reduce the product by factoring the top and the bottom, then cancel. Example A. Simplify 10x y3z a. * y2 5x3 = 10xy2 5x3y3z
  • 6.
    Multiplication Rule forRational Expressions A B C D * = AC BD Multiplication and Division of Rational Expressions In most problems, we reduce the product by factoring the top and the bottom, then cancel. Example A. Simplify 10x y3z a. * y2 5x3 = 10xy2 5x3y3z = 2 x2yz
  • 7.
    Multiplication Rule forRational Expressions A B C D * = AC BD Multiplication and Division of Rational Expressions In most problems, we reduce the product by factoring the top and the bottom, then cancel. Example A. Simplify 10x y3z a. * y2 5x3 = 10xy2 5x3y3z = 2 x2yz b. (x2 + 2x – 3 ) (x – 2) (x2 – x ) (x2 – 4 ) *
  • 8.
    Multiplication Rule forRational Expressions A B C D * = AC BD Multiplication and Division of Rational Expressions In most problems, we reduce the product by factoring the top and the bottom, then cancel. Example A. Simplify 10x y3z a. * y2 5x3 = 10xy2 5x3y3z = 2 x2yz b. (x2 + 2x – 3 ) (x – 2) (x2 – x ) (x2 – 4 ) * = (x + 3)(x – 1 )
  • 9.
    Multiplication Rule forRational Expressions A B C D * = AC BD Multiplication and Division of Rational Expressions In most problems, we reduce the product by factoring the top and the bottom, then cancel. Example A. Simplify 10x y3z a. * y2 5x3 = 10xy2 5x3y3z = 2 x2yz b. (x2 + 2x – 3 ) (x – 2) (x2 – x ) (x2 – 4 ) * = (x + 3)(x – 1 ) (x + 2 )(x – 2)
  • 10.
    Multiplication Rule forRational Expressions A B C D * = AC BD Multiplication and Division of Rational Expressions In most problems, we reduce the product by factoring the top and the bottom, then cancel. Example A. Simplify 10x y3z a. * y2 5x3 = 10xy2 5x3y3z = 2 x2yz b. (x2 + 2x – 3 ) (x – 2) (x2 – x ) (x2 – 4 ) * = (x + 3)(x – 1 ) (x – 2) (x + 2 )(x – 2)
  • 11.
    Multiplication Rule forRational Expressions A B C D * = AC BD Multiplication and Division of Rational Expressions In most problems, we reduce the product by factoring the top and the bottom, then cancel. Example A. Simplify 10x y3z a. * y2 5x3 = 10xy2 5x3y3z = 2 x2yz b. (x2 + 2x – 3 ) (x – 2) (x2 – x ) (x2 – 4 ) * = (x + 3)(x – 1 ) (x – 2) x(x – 1 ) (x + 2 )(x – 2)
  • 12.
    Multiplication Rule forRational Expressions A B C D * = AC BD Multiplication and Division of Rational Expressions In most problems, we reduce the product by factoring the top and the bottom, then cancel. Example A. Simplify 10x y3z a. * y2 5x3 = 10xy2 5x3y3z = 2 x2yz b. (x2 + 2x – 3 ) (x – 2) (x2 – x ) (x2 – 4 ) * = (x + 3)(x – 1 ) (x – 2) x(x – 1 ) (x + 2 )(x – 2)
  • 13.
    Multiplication Rule forRational Expressions A B C D * = AC BD Multiplication and Division of Rational Expressions In most problems, we reduce the product by factoring the top and the bottom, then cancel. Example A. Simplify 10x y3z a. * y2 5x3 = 10xy2 5x3y3z = 2 x2yz b. (x2 + 2x – 3 ) (x – 2) (x2 – x ) (x2 – 4 ) * = (x + 3)(x – 1 ) (x – 2) x(x – 1 ) (x + 2 )(x – 2)
  • 14.
    Multiplication Rule forRational Expressions A B C D * = AC BD Multiplication and Division of Rational Expressions In most problems, we reduce the product by factoring the top and the bottom, then cancel. Example A. Simplify 10x y3z a. * y2 5x3 = 10xy2 5x3y3z = 2 x2yz b. (x2 + 2x – 3 ) (x – 2) (x2 – x ) (x2 – 4 ) = (x + 3)(x + 2) x * = (x + 3)(x – 1 ) (x – 2) x(x – 1 ) (x + 2 )(x – 2) In the next section, we meet the following type of problems.
  • 15.
    Multiplication and Divisionof Rational Expressions Example B. Simplify and expand the answers. a. x + 3 x – 1 (x2 – 1)
  • 16.
    Multiplication and Divisionof Rational Expressions a. x + 3 x – 1 (x2 – 1) = x + 3 (x – 1) (x – 1)(x + 1) Example B. Simplify and expand the answers.
  • 17.
    Multiplication and Divisionof Rational Expressions Example B. Simplify and expand the answers. a. x + 3 x – 1 (x2 – 1) = x + 3 (x – 1) (x – 1)(x + 1) = (x + 3)(x + 1)
  • 18.
    Multiplication and Divisionof Rational Expressions a. x + 3 x – 1 (x2 – 1) = x + 3 (x – 1) (x – 1)(x + 1) = (x + 3)(x + 1) = x2 + 4x + 3 Example B. Simplify and expand the answers.
  • 19.
    Multiplication and Divisionof Rational Expressions a. x + 3 x – 1 (x2 – 1) = x + 3 (x – 1) (x – 1)(x + 1) = (x + 3)(x + 1) = x2 + 4x + 3 b. x – 2 x2 – 9 ( – x + 1 x2 – 2x – 3 ) ( x – 3)(x + 3)(x + 1) Example B. Simplify and expand the answers.
  • 20.
    Multiplication and Divisionof Rational Expressions a. x + 3 x – 1 (x2 – 1) = x + 3 (x – 1) (x – 1)(x + 1) = (x + 3)(x + 1) = x2 + 4x + 3 b. x – 2 x2 – 9 ( – x + 1 x2 – 2x – 3 ) ( x – 3)(x + 3)(x + 1) = x – 2 (x – 3)(x + 3) Example B. Simplify and expand the answers.
  • 21.
    Multiplication and Divisionof Rational Expressions a. x + 3 x – 1 (x2 – 1) = x + 3 (x – 1) (x – 1)(x + 1) = (x + 3)(x + 1) = x2 + 4x + 3 b. x – 2 x2 – 9 ( – x + 1 x2 – 2x – 3 ) ( x – 3)(x + 3)(x + 1) = x – 2 (x – 3)(x + 3) – x + 1 (x – 3)(x + 1) Example B. Simplify and expand the answers.
  • 22.
    Multiplication and Divisionof Rational Expressions a. x + 3 x – 1 (x2 – 1) = x + 3 (x – 1) (x – 1)(x + 1) = (x + 3)(x + 1) = x2 + 4x + 3 b. x – 2 x2 – 9 ( – x + 1 x2 – 2x – 3 ) ( x – 3)(x + 3)(x + 1) = x – 2 (x – 3)(x + 3) [ – x + 1 (x – 3)(x + 1) ] ( x – 3)(x + 3)(x + 1) Example B. Simplify and expand the answers.
  • 23.
    Multiplication and Divisionof Rational Expressions a. x + 3 x – 1 (x2 – 1) = x + 3 (x – 1) (x – 1)(x + 1) = (x + 3)(x + 1) = x2 + 4x + 3 b. x – 2 x2 – 9 ( – x + 1 x2 – 2x – 3 ) ( x – 3)(x + 3)(x + 1) = x – 2 (x – 3)(x + 3) [ – x + 1 (x – 3)(x + 1) ] ( x – 3)(x + 3)(x + 1) (x + 1) Example B. Simplify and expand the answers.
  • 24.
    Multiplication and Divisionof Rational Expressions a. x + 3 x – 1 (x2 – 1) = x + 3 (x – 1) (x – 1)(x + 1) = (x + 3)(x + 1) = x2 + 4x + 3 b. x – 2 x2 – 9 ( – x + 1 x2 – 2x – 3 ) ( x – 3)(x + 3)(x + 1) = x – 2 (x – 3)(x + 3) [ – x + 1 (x – 3)(x + 1) ] ( x – 3)(x + 3)(x + 1) (x + 1) (x + 3) Example B. Simplify and expand the answers.
  • 25.
    Multiplication and Divisionof Rational Expressions a. x + 3 x – 1 (x2 – 1) = x + 3 (x – 1) (x – 1)(x + 1) = (x + 3)(x + 1) = x2 + 4x + 3 b. x – 2 x2 – 9 ( – x + 1 x2 – 2x – 3 ) ( x – 3)(x + 3)(x + 1) = x – 2 (x – 3)(x + 3) [ – x + 1 (x – 3)(x + 1) ] ( x – 3)(x + 3)(x + 1) (x + 1) (x + 3) = (x – 2)(x + 1) – (x + 1)(x + 3) Example B. Simplify and expand the answers.
  • 26.
    Multiplication and Divisionof Rational Expressions a. x + 3 x – 1 (x2 – 1) = x + 3 (x – 1) (x – 1)(x + 1) = (x + 3)(x + 1) = x2 + 4x + 3 b. x – 2 x2 – 9 ( – x + 1 x2 – 2x – 3 ) ( x – 3)(x + 3)(x + 1) = x – 2 (x – 3)(x + 3) [ – x + 1 (x – 3)(x + 1) ] ( x – 3)(x + 3)(x + 1) (x + 1) (x + 3) = (x – 2)(x + 1) – (x + 1)(x + 3) = (x – 2)(x + 1) + (–x –1)(x + 3) Example B. Simplify and expand the answers.
  • 27.
    Multiplication and Divisionof Rational Expressions a. x + 3 x – 1 (x2 – 1) = x + 3 (x – 1) (x – 1)(x + 1) = (x + 3)(x + 1) = x2 + 4x + 3 b. x – 2 x2 – 9 ( – x + 1 x2 – 2x – 3 ) ( x – 3)(x + 3)(x + 1) = x – 2 (x – 3)(x + 3) [ – x + 1 (x – 3)(x + 1) ] ( x – 3)(x + 3)(x + 1) (x + 1) (x + 3) = (x – 2)(x + 1) – (x + 1)(x + 3) = (x – 2)(x + 1) + (–x –1)(x + 3) = x2 – x – 2 – x2 – 4x – 3 Example B. Simplify and expand the answers.
  • 28.
    Multiplication and Divisionof Rational Expressions Example B. Simplify and expand the answers. a. x + 3 x – 1 (x2 – 1) = x + 3 (x – 1) (x – 1)(x + 1) = (x + 3)(x + 1) = x2 + 4x + 3 b. x – 2 x2 – 9 ( – x + 1 x2 – 2x – 3 ) ( x – 3)(x + 3)(x + 1) = x – 2 (x – 3)(x + 3) [ – x + 1 (x – 3)(x + 1) ] ( x – 3)(x + 3)(x + 1) (x + 1) (x + 3) = (x – 2)(x + 1) – (x + 1)(x + 3) = (x – 2)(x + 1) + (–x –1)(x + 3) = x2 – x – 2 – x2 – 4x – 3 = –5x – 5
  • 29.
    Division Rule forRational Expressions Multiplication and Division of Rational Expressions A B C D ÷
  • 30.
    Division Rule forRational Expressions Multiplication and Division of Rational Expressions A B C D ÷ = AD BC Reciprocate
  • 31.
    Division Rule forRational Expressions Multiplication and Division of Rational Expressions A B C D ÷ = AD BC Reciprocate We convert division by an expression of multiplying by its reciprocal.
  • 32.
    Division Rule forRational Expressions Multiplication and Division of Rational Expressions A B C D ÷ = AD BC Reciprocate We convert division by an expression of multiplying by its reciprocal. Then we factor and reduce the product.
  • 33.
    Division Rule forRational Expressions Multiplication and Division of Rational Expressions A B C D ÷ = AD BC Reciprocate (2x – 6) (x + 3) ÷ (x2 + 2x – 3) (9 – x2) Example C. Simplify We convert division by an expression of multiplying by its reciprocal. Then we factor and reduce the product.
  • 34.
    Division Rule forRational Expressions Multiplication and Division of Rational Expressions A B C D ÷ = AD BC Reciprocate (2x – 6) (x + 3) ÷ (x2 + 2x – 3) (9 – x2) = (2x – 6) (x + 3) (x2 + 2x – 3) (9 – x2) * Example C. Simplify We convert division by an expression of multiplying by its reciprocal. Then we factor and reduce the product.
  • 35.
    Division Rule forRational Expressions Multiplication and Division of Rational Expressions A B C D ÷ = AD BC Reciprocate (2x – 6) (x + 3) ÷ (x2 + 2x – 3) (9 – x2) = (2x – 6) (x + 3) (x2 + 2x – 3) (9 – x2) * = 2(x – 3) (x + 3) Example C. Simplify We convert division by an expression of multiplying by its reciprocal. Then we factor and reduce the product.
  • 36.
    Division Rule forRational Expressions Multiplication and Division of Rational Expressions A B C D ÷ = AD BC Reciprocate (2x – 6) (x + 3) ÷ (x2 + 2x – 3) (9 – x2) = (2x – 6) (x + 3) (x2 + 2x – 3) (9 – x2) * = 2(x – 3) (x + 3) (x + 3)(x – 1) (3 – x)(3 + x) Example C. Simplify We convert division by an expression of multiplying by its reciprocal. Then we factor and reduce the product.
  • 37.
    Division Rule forRational Expressions Multiplication and Division of Rational Expressions A B C D ÷ = AD BC Reciprocate Example C. Simplify (2x – 6) (x + 3) ÷ (x2 + 2x – 3) (9 – x2) = (2x – 6) (x + 3) (x2 + 2x – 3) (9 – x2) * = 2(x – 3) (x + 3) (x + 3)(x – 1) (3 – x)(3 + x) * (9 – x2) We convert division by an expression of multiplying by its reciprocal. Then we factor and reduce the product.
  • 38.
    Division Rule forRational Expressions Multiplication and Division of Rational Expressions A B C D ÷ = AD BC Reciprocate (2x – 6) (x + 3) ÷ (x2 + 2x – 3) (9 – x2) = (2x – 6) (x + 3) (x2 + 2x – 3) (9 – x2) * = 2(x – 3) (x + 3) (x + 3)(x – 1) (3 – x)(3 + x) * (–1) Example C. Simplify We convert division by an expression of multiplying by its reciprocal. Then we factor and reduce the product.
  • 39.
    Division Rule forRational Expressions Multiplication and Division of Rational Expressions A B C D ÷ = AD BC Reciprocate (2x – 6) (x + 3) ÷ (x2 + 2x – 3) (9 – x2) = (2x – 6) (x + 3) (x2 + 2x – 3) (9 – x2) * = 2(x – 3) (x + 3) (x + 3)(x – 1) (3 – x)(3 + x) * (–1) = –2(x – 1) (3 + x) Example C. Simplify We convert division by an expression of multiplying by its reciprocal. Then we factor and reduce the product.
  • 40.
    Multiplication and Divisionof Rational Expressions Besides the expanded form and factored forms, rational expressions may also be split into sums or differences.
  • 41.
    Multiplication and Divisionof Rational Expressions Besides the expanded form and factored forms, rational expressions may also be split into sums or differences. There are two common ways to do this.
  • 42.
    Multiplication and Divisionof Rational Expressions Besides the expanded form and factored forms, rational expressions may also be split into sums or differences. There are two common ways to do this. I. Split off the numerator term by term.
  • 43.
    Multiplication and Divisionof Rational Expressions Example D. Break up the numerators as the sums or differences and simplify each term. (2x – 6) (x + 3) a. = Besides the expanded form and factored forms, rational expressions may also be split into sums or differences. There are two common ways to do this. I. Split off the numerator term by term. (2x – 6) 3x2 b. =
  • 44.
    Multiplication and Divisionof Rational Expressions Example D. Break up the numerators as the sums or differences and simplify each term. (2x – 6) (x + 3) a. = Besides the expanded form and factored forms, rational expressions may also be split into sums or differences. There are two common ways to do this. I. Split off the numerator term by term. (x + 3) – (x + 3) 2x 6 (2x – 6) 3x2 b. =
  • 45.
    Multiplication and Divisionof Rational Expressions Example D. Break up the numerators as the sums or differences and simplify each term. (2x – 6) (x + 3) a. = Besides the expanded form and factored forms, rational expressions may also be split into sums or differences. There are two common ways to do this. I. Split off the numerator term by term. (x + 3) – (x + 3) 2x 6 (2x – 6) 3x2 b. = – 2x 6 3x2 3x2
  • 46.
    Multiplication and Divisionof Rational Expressions Example D. Break up the numerators as the sums or differences and simplify each term. (2x – 6) (x + 3) a. = Besides the expanded form and factored forms, rational expressions may also be split into sums or differences. There are two common ways to do this. I. Split off the numerator term by term. (x + 3) – (x + 3) 2x 6 (2x – 6) 3x2 b. = – 2x 6 3x2 3x2 = – 2 x2 2 3x
  • 47.
    Multiplication and Divisionof Rational Expressions Example D. Break up the numerators as the sums or differences and simplify each term. (2x – 6) (x + 3) a. = Besides the expanded form and factored forms, rational expressions may also be split into sums or differences. There are two common ways to do this. I. Split off the numerator term by term. (x + 3) – (x + 3) 2x 6 (2x – 6) 3x2 b. = – 2x 6 3x2 3x2 = – 2 x2 2 3x II. Long Division Long division is the extension of the long division of numbers from grade school and it is for the division of polynomials in one variable.
  • 48.
    Multiplication and Divisionof Rational Expressions Example D. Break up the numerators as the sums or differences and simplify each term. (2x – 6) (x + 3) a. = Besides the expanded form and factored forms, rational expressions may also be split into sums or differences. There are two common ways to do this. I. Split off the numerator term by term. (x + 3) – (x + 3) 2x 6 (2x – 6) 3x2 b. = – 2x 6 3x2 3x2 = – 2 x2 2 3x II. Long Division Long division is the extension of the long division of numbers from grade school and it is for the division of polynomials in one variable. Specifically, long division gives relevant results only when the degree of the numerator is the same or more than the degree of the denominator.
  • 49.
    Multiplication and Divisionof Rational Expressions Let’s look at the example 125/8 or 125 ÷ 8 by long division.
  • 50.
    Multiplication and Divisionof Rational Expressions Let’s look at the example 125/8 or 125 ÷ 8 by long division. i. Put the problem in the long division format with the “bottom-out” and move from left to right until there is enough to enter a quotient.
  • 51.
    Multiplication and Divisionof Rational Expressions Let’s look at the example 125/8 or 125 ÷ 8 by long division. i. Put the problem in the long division format with the “bottom-out” and move from left to right until there is enough to enter a quotient. )8 125
  • 52.
    Multiplication and Divisionof Rational Expressions Let’s look at the example 125/8 or 125 ÷ 8 by long division. i. Put the problem in the long division format with the “bottom-out” and move from left to right until there is enough to enter a quotient. )8 125 1
  • 53.
    Multiplication and Divisionof Rational Expressions Let’s look at the example 125/8 or 125 ÷ 8 by long division. i. Put the problem in the long division format with the “bottom-out” and move from left to right until there is enough to enter a quotient. )8 125 1 ii. Multiply the quotient back into the problem and subtract the results from the numerator. Bring down the remaining terms from the numerator. 8 45
  • 54.
    Multiplication and Divisionof Rational Expressions Let’s look at the example 125/8 or 125 ÷ 8 by long division. i. Put the problem in the long division format with the “bottom-out” and move from left to right until there is enough to enter a quotient. )8 125 1 ii. Multiply the quotient back into the problem and subtract the results from the numerator. Bring down the remaining terms from the numerator. 8 45 iii. Repeat steps i and ii until no more quotient may be entered.
  • 55.
    Multiplication and Divisionof Rational Expressions i. Put the problem in the long division format with the “bottom-out” and move from left to right until there is enough to enter a quotient. )8 125 15 ii. Multiply the quotient back into the problem and subtract the results from the numerator. Bring down the remaining terms from the numerator. 8 45 iii. Repeat steps i and ii until no more quotient may be entered. 40 5 Let’s look at the example 125/8 or 125 ÷ 8 by long division.
  • 56.
    Multiplication and Divisionof Rational Expressions i. Put the problem in the long division format with the “bottom-out” and move from left to right until there is enough to enter a quotient. )8 125 15 ii. Multiply the quotient back into the problem and subtract the results from the numerator. Bring down the remaining terms from the numerator. 8 45 iii. Repeat steps i and ii until no more quotient may be entered. Then we may put the fraction N/D in the following mixed form: N D = Q + R D and that R (the remainder) is smaller then D (no more quotient). 40 5 where Q is the quotient Let’s look at the example 125/8 or 125 ÷ 8 by long division.
  • 57.
    Multiplication and Divisionof Rational Expressions i. Put the problem in the long division format with the “bottom-out” and move from left to right until there is enough to enter a quotient. )8 125 15 ii. Multiply the quotient back into the problem and subtract the results from the numerator. Bring down the remaining terms from the numerator. 8 45 iii. Repeat steps i and ii until no more quotient may be entered. Then we may put the fraction N/D in the following mixed form: N D = Q + R D and that R (the remainder) is smaller then D (no more quotient). 40 5 125 8 = 15 + 5 8 where Q is the quotient Let’s look at the example 125/8 or 125 ÷ 8 by long division.
  • 58.
    Multiplication and Divisionof Rational Expressions Example E. Divide using long division(2x – 6) (x + 3)
  • 59.
    Multiplication and Divisionof Rational Expressions i. Put the problem in the long division format with the “bottom-out” and enter the quotients of the leading terms. Example E. Divide using long division(2x – 6) (x + 3)
  • 60.
    Multiplication and Divisionof Rational Expressions )x + 3 2x – 6 i. Put the problem in the long division format with the “bottom-out” and enter the quotients of the leading terms. Make sure the terms are in order. Example E. Divide using long division(2x – 6) (x + 3)
  • 61.
    Multiplication and Divisionof Rational Expressions )x + 3 2x – 6 i. Put the problem in the long division format with the “bottom-out” and enter the quotients of the leading terms. Make sure the terms are in order. Example E. Divide using long division(2x – 6) (x + 3)
  • 62.
    Multiplication and Divisionof Rational Expressions )x + 3 2x – 6 i. Put the problem in the long division format with the “bottom-out” and enter the quotients of the leading terms. enter the quotients of the leading terms 2x/x = 2 Example E. Divide using long division(2x – 6) (x + 3)
  • 63.
    Multiplication and Divisionof Rational Expressions )x + 3 2x – 6 2 i. Put the problem in the long division format with the “bottom-out” and enter the quotients of the leading terms. enter the quotients of the leading terms 2x/x = 2 Example E. Divide using long division(2x – 6) (x + 3)
  • 64.
    Multiplication and Divisionof Rational Expressions )x + 3 2x – 6 2 ii. Multiply the quotient back into the problem and subtract the results from the numerator. Bring down the remaining terms from the numerator. i. Put the problem in the long division format with the “bottom-out” and enter the quotients of the leading terms. Example E. Divide using long division(2x – 6) (x + 3)
  • 65.
    Multiplication and Divisionof Rational Expressions )x + 3 2x – 6 2 2x + 6 ii. Multiply the quotient back into the problem and subtract the results from the numerator. Bring down the remaining terms from the numerator. i. Put the problem in the long division format with the “bottom-out” and enter the quotients of the leading terms. Example E. Divide using long division(2x – 6) (x + 3)
  • 66.
    Multiplication and Divisionof Rational Expressions )x + 3 2x – 6 2 ii. Multiply the quotient back into the problem and subtract the results from the numerator. Bring down the remaining terms from the numerator. 2x + 6 –12 –) i. Put the problem in the long division format with the “bottom-out” and enter the quotients of the leading terms. Example E. Divide using long division(2x – 6) (x + 3)
  • 67.
    Multiplication and Divisionof Rational Expressions )x + 3 2x – 6 2 ii. Multiply the quotient back into the problem and subtract the results from the numerator. Bring down the remaining terms from the numerator. 2x + 6 –12 iii. Repeat steps i and ii until no more quotient may be entered. –) i. Put the problem in the long division format with the “bottom-out” and enter the quotients of the leading terms. Example E. Divide using long division(2x – 6) (x + 3)
  • 68.
    Multiplication and Divisionof Rational Expressions )x + 3 2x – 6 2 ii. Multiply the quotient back into the problem and subtract the results from the numerator. Bring down the remaining terms from the numerator. 2x + 6 –12 –) Stop. No more quotient since x can’t going into 12. iii. Repeat steps i and ii until no more quotient may be entered. i. Put the problem in the long division format with the “bottom-out” and enter the quotients of the leading terms. Example E. Divide using long division(2x – 6) (x + 3)
  • 69.
    Multiplication and Divisionof Rational Expressions )x + 3 2x – 6 2 ii. Multiply the quotient back into the problem and subtract the results from the numerator. Bring down the remaining terms from the numerator. 2x + 6 –12 iii. Repeat steps i and ii until no more quotient may be entered. Then we may put the fraction N/D in the following mixed form: –) N D = Q + R D has smaller degree then denominator D (no more quotient). where Q is the quotient and the remainder R i. Put the problem in the long division format with the “bottom-out” and enter the quotients of the leading terms. Example E. Divide using long division(2x – 6) (x + 3)
  • 70.
    Multiplication and Divisionof Rational Expressions )x + 3 2x – 6 2 ii. Multiply the quotient back into the problem and subtract the results from the numerator. Bring down the remaining terms from the numerator. 2x + 6 –12 iii. Repeat steps i and ii until no more quotient may be entered. Then we may put the fraction N/D in the following mixed form: –) Hence we may write (2x – 6) (x + 3) N D = Q + R D has smaller degree then denominator D (no more quotient). where Q is the quotient and the remainder R i. Put the problem in the long division format with the “bottom-out” and enter the quotients of the leading terms. Example E. Divide using long division(2x – 6) (x + 3)
  • 71.
    Multiplication and Divisionof Rational Expressions )x + 3 2x – 6 2 ii. Multiply the quotient back into the problem and subtract the results from the numerator. Bring down the remaining terms from the numerator. 2x + 6 –12 iii. Repeat steps i and ii until no more quotient may be entered. Then we may put the fraction N/D in the following mixed form: –) Hence we may write (2x – 6) (x + 3) N D = Q + R D has smaller degree then denominator D (no more quotient). where Q is the quotient and the remainder R i. Put the problem in the long division format with the “bottom-out” and enter the quotients of the leading terms. Q R Example E. Divide using long division(2x – 6) (x + 3)
  • 72.
    Multiplication and Divisionof Rational Expressions )x + 3 2x – 6 2 ii. Multiply the quotient back into the problem and subtract the results from the numerator. Bring down the remaining terms from the numerator. 2x + 6 –12 iii. Repeat steps i and ii until no more quotient may be entered. Then we may put the fraction N/D in the following mixed form: = 2 – 12 x + 3 –) Hence we may write (2x – 6) (x + 3) N D = Q + R D has smaller degree then denominator D (no more quotient). where Q is the quotient and the remainder R i. Put the problem in the long division format with the “bottom-out” and enter the quotients of the leading terms. Q R Q R Example E. Divide using long division(2x – 6) (x + 3)
  • 73.
    Multiplication and Divisionof Rational Expressions Example F. Divide using long division ii. Multiply the quotient back into the problem and subtract the results from the numerator. Bring down the remaining terms from the numerator. iii. Repeat steps i and ii until no more quotient may be entered. Then we may put the fraction N/D in the following mixed form: x2 – 6x + 3 x – 2 N D = Q + R D has smaller degree then denominator D (no more quotient). where Q is the quotient and the remainder R i. Put the problem in the long division format with the “bottom-out” and enter the quotients of the leading terms.
  • 74.
    Multiplication and Divisionof Rational Expressions )x + 3 ii. Multiply the quotient back into the problem and subtract the results from the numerator. Bring down the remaining terms from the numerator. iii. Repeat steps i and ii until no more quotient may be entered. Then we may put the fraction N/D in the following mixed form: x2 – 6x + 3 Make sure the terms are in order. N D = Q + R D has smaller degree then denominator D (no more quotient). where Q is the quotient and the remainder R i. Put the problem in the long division format with the “bottom-out” and enter the quotients of the leading terms. Example F. Divide using long divisionx2 – 6x + 3 x – 2
  • 75.
    Multiplication and Divisionof Rational Expressions )x + 3 ii. Multiply the quotient back into the problem and subtract the results from the numerator. Bring down the remaining terms from the numerator. iii. Repeat steps i and ii until no more quotient may be entered. Then we may put the fraction N/D in the following mixed form: x2 – 6x + 3 N D = Q + R D has smaller degree then denominator D (no more quotient). where Q is the quotient and the remainder R i. Put the problem in the long division format with the “bottom-out” and enter the quotients of the leading terms. Example F. Divide using long divisionx2 – 6x + 3 x – 2
  • 76.
    Multiplication and Divisionof Rational Expressions )x + 3 x ii. Multiply the quotient back into the problem and subtract the results from the numerator. Bring down the remaining terms from the numerator. iii. Repeat steps i and ii until no more quotient may be entered. Then we may put the fraction N/D in the following mixed form: x2 – 6x + 3 N D = Q + R D has smaller degree then denominator D (no more quotient). where Q is the quotient and the remainder R i. Put the problem in the long division format with the “bottom-out” and enter the quotients of the leading terms. Example F. Divide using long divisionx2 – 6x + 3 x – 2
  • 77.
    Multiplication and Divisionof Rational Expressions )x + 3 x ii. Multiply the quotient back into the problem and subtract the results from the numerator. Bring down the remaining terms from the numerator. x2 + 3x iii. Repeat steps i and ii until no more quotient may be entered. Then we may put the fraction N/D in the following mixed form: x2 – 6x + 3 N D = Q + R D has smaller degree then denominator D (no more quotient). where Q is the quotient and the remainder R i. Put the problem in the long division format with the “bottom-out” and enter the quotients of the leading terms. Example F. Divide using long divisionx2 – 6x + 3 x – 2
  • 78.
    Multiplication and Divisionof Rational Expressions )x + 3 x ii. Multiply the quotient back into the problem and subtract the results from the numerator. Bring down the remaining terms from the numerator. x2 + 3x –9x + 3 iii. Repeat steps i and ii until no more quotient may be entered. Then we may put the fraction N/D in the following mixed form: –) x2 – 6x + 3 N D = Q + R D has smaller degree then denominator D (no more quotient). where Q is the quotient and the remainder R i. Put the problem in the long division format with the “bottom-out” and enter the quotients of the leading terms. Example F. Divide using long divisionx2 – 6x + 3 x – 2
  • 79.
    Multiplication and Divisionof Rational Expressions )x + 3 x – 9 ii. Multiply the quotient back into the problem and subtract the results from the numerator. Bring down the remaining terms from the numerator. x2 + 3x –9x + 3 iii. Repeat steps i and ii until no more quotient may be entered. Then we may put the fraction N/D in the following mixed form: –) x2 – 6x + 3 N D = Q + R D has smaller degree then denominator D (no more quotient). where Q is the quotient and the remainder R i. Put the problem in the long division format with the “bottom-out” and enter the quotients of the leading terms. Example F. Divide using long divisionx2 – 6x + 3 x – 2
  • 80.
    Multiplication and Divisionof Rational Expressions )x + 3 x – 9 ii. Multiply the quotient back into the problem and subtract the results from the numerator. Bring down the remaining terms from the numerator. x2 + 3x –9x + 3 iii. Repeat steps i and ii until no more quotient may be entered. Then we may put the fraction N/D in the following mixed form: –) x2 – 6x + 3 –9x – 27 N D = Q + R D has smaller degree then denominator D (no more quotient). where Q is the quotient and the remainder R i. Put the problem in the long division format with the “bottom-out” and enter the quotients of the leading terms. Example F. Divide using long divisionx2 – 6x + 3 x – 2
  • 81.
    Multiplication and Divisionof Rational Expressions )x + 3 x – 9 ii. Multiply the quotient back into the problem and subtract the results from the numerator. Bring down the remaining terms from the numerator. x2 + 3x –9x + 3 iii. Repeat steps i and ii until no more quotient may be entered. Then we may put the fraction N/D in the following mixed form: –) x2 – 6x + 3 –9x – 27–) 30 N D = Q + R D has smaller degree then denominator D (no more quotient). where Q is the quotient and the remainder R i. Put the problem in the long division format with the “bottom-out” and enter the quotients of the leading terms. Example F. Divide using long divisionx2 – 6x + 3 x – 2
  • 82.
    Multiplication and Divisionof Rational Expressions )x + 3 x – 9 ii. Multiply the quotient back into the problem and subtract the results from the numerator. Bring down the remaining terms from the numerator. x2 + 3x –9x + 3 iii. Repeat steps i and ii until no more quotient may be entered. Then we may put the fraction N/D in the following mixed form: N D = Q + R D has smaller degree then denominator D (no more quotient). where Q is the quotient –) x2 – 6x + 3 –9x – 27–) 30 Stop. No more quotient since x can’t going into 30. Hence 30 is the remainder. and the remainder R i. Put the problem in the long division format with the “bottom-out” and enter the quotients of the leading terms. Example F. Divide using long divisionx2 – 6x + 3 x – 2
  • 83.
    Multiplication and Divisionof Rational Expressions )x + 3 x – 9 ii. Multiply the quotient back into the problem and subtract the results from the numerator. Bring down the remaining terms from the numerator. x2 + 3x –9x + 3 iii. Repeat steps i and ii until no more quotient may be entered. Then we may put the fraction N/D in the following mixed form: –) x2 – 6x + 3 –9x – 27–) 30 Hence x2 – 6x + 3 x – 2 = N D = Q + R D has smaller degree then denominator D (no more quotient). where Q is the quotient and the remainder R i. Put the problem in the long division format with the “bottom-out” and enter the quotients of the leading terms. Example F. Divide using long divisionx2 – 6x + 3 x – 2
  • 84.
    Multiplication and Divisionof Rational Expressions )x + 3 x – 9 ii. Multiply the quotient back into the problem and subtract the results from the numerator. Bring down the remaining terms from the numerator. x2 + 3x –9x + 3 iii. Repeat steps i and ii until no more quotient may be entered. Then we may put the fraction N/D in the following mixed form: –) x2 – 6x + 3 –9x – 27–) 30 Hence x2 – 6x + 3 x – 2 = x – 9 + 30 x + 3 i. Put the problem in the long division format with the “bottom-out” and enter the quotients of the leading terms. N D = Q + R D has smaller degree then denominator D (no more quotient). where Q is the quotient and the remainder R Example F. Divide using long divisionx2 – 6x + 3 x – 2
  • 85.
    Ex A. Simplify.Do not expand the results. Multiplication and Division of Rational Expressions 1. 10x * 2 5x3 15x 4 * 16 25x4 10x * 35x32. 5. 10 9x4 * 18 5x3 6. 3.12x6* 5 6x14 56x6 27 * 63 8x5 10x * 35x34. 7. 75x 49 * 42 25x3 8. 9. 2x – 4 2x + 4 5x + 10 3x – 6 10. 6 – 4x 3x – 2 x – 2 2x + 4 11. 9x – 12 2x – 4 2 – x 8 – 6x 12. x + 4 –x – 4 4 – x x – 4 13. 3x – 9 15x – 5 3 – x 5 – 15x 14. 42 – 6x –2x + 14 4 – 2x –7x + 14 * * * * * * 15. (x2 + x – 2 ) (x – 2) (x2 – x) (x2 – 4 ) * 16. (x2 + 2x – 3 ) (x2 – 9) (x2 – x – 2 ) (x2 – 2x – 3) * 17. (x2 – x – 2 ) (x2 – 1) (x2 + 2x + 1) (x2 + x ) * 18. (x2 + 5x – 6 ) (x2 + 5x + 6) (x2 – 5x – 6 ) (x2 – 5x + 6) * 19. (x2 – 3x – 4 ) (x2 – 1) (x2 – 2x – 8) (x2 – 3x + 2) * 20. (– x2 + 6 – x ) (x2 + 5x + 6) (x2 – x – 12 ) (6 – x2 – x) *
  • 86.
    Ex. A. Simplify.Do not expand the results. Multiplication and Division of Rational Expressions 21. (2x2 + x – 1 ) (1 – 2x) (4x2 – 1) (2x2 – x ) 22. (3x2 – 2x – 1) (1 – 9x2) (x2 + x – 2 ) (x2 + 4x + 4) 23.(3x2 – x – 2) (x2 – x + 2) (3x2 + 4x + 1) (–x – 3x2) 24. (x + 1 – 6x2) (–x2 – 4) (2x2 + x – 1 ) (x2 – 5x – 6) 25. (x3 – 4x) (–x2 + 4x – 4) (x2 + 2) (–x + 2) 26. (–x3 + 9x ) (x2 + 6x + 9) (x2 + 3x) (–3x2 – 9x) Ex. B. Multiply, expand and simplify the results. ÷ ÷ ÷ ÷ ÷ ÷ 27. x + 3 x + 1 (x2 – 1) 28. x – 3 x – 2 (x2 – 4) 29. 2x + 3 1 – x (x2 – 1) 30. 3 – 2x x + 2 (x + 2)(x +1) 31. 3 – 2x 2x – 1 (3x + 2)(1 – 2x) 32. x – 2 x – 3 ( + x + 1 x + 3 )( x – 3)(x + 3) 33. 2x – 1 x + 2 ( – x + 2 2x – 3 ) ( 2x – 3)(x + 2)
  • 87.
    Multiplication and Divisionof Rational Expressions 38. x – 2 x2 – 9 ( – x + 1 x2 – 2x – 3 ) ( x – 3)(x + 3)(x + 1) 39. x + 3 x2 – 4 ( – 2x + 1 x2 + x – 2 ) ( x – 2)(x + 2)(x – 1) 40. x – 1 x2 – x – 6 ( – x + 1 x2 – 2x – 3 ) ( x – 3)(x + 2)(x + 1) 41. x + 2 x2 – 4x +3 ( – 2x + 1 x2 + 2x – 3 )( x – 3)(x + 3)(x – 1) 34. 4 – x x – 3 ( – x – 1 2x + 3 )( x – 3)(2x + 3) 35. 3 – x x + 2 ( – 2x + 3 x – 3 )(x – 3)(x + 2) Ex B. Multiply, expand and simplify the results. 36. 3 – 4x x + 1 ( – 1 – 2x x + 3 )( x + 3)(x + 1) 37. 5x – 7 x + 5 ( – 4 – 5x x – 3 )(x – 3)(x + 5)
  • 88.
    Ex. C. Breakup the following expressions as sums and differences of fractions. 42. 43. 44. 45. 46. 47. x2 + 4x – 6 2x2x2 – 4 x2 12x3 – 9x2 + 6x 3x x2 – 4 2x x x8 – x6 – x4 x2 x8 – x6 – x4 Ex D. Use long division and write each rational expression in the form of Q + . R D (x2 + x – 2 ) (x – 1) (3x2 – 3x – 2 ) (x + 2) 2x + 6 x + 2 48. 3x – 5 x – 2 49. 4x + 3 x – 1 50. 5x – 4 x – 3 51. 3x + 8 2 – x 52. –4x – 5 1 – x 53. 54. (2x2 + x – 3 ) (x – 2) 55. 56. (–x2 + 4x – 3 ) (x – 3) (5x2 – 1 ) (x – 4) 57. (4x2 + 2 ) (x + 3) 58. 59. Multiplication and Division of Rational Expressions