Applications of Factoring
Applications of Factoring
There are many applications of the factored forms of
polynomials.
Applications of Factoring
There are many applications of the factored forms of
polynomials. Following are some of them:
Applications of Factoring
There are many applications of the factored forms of
polynomials. Following are some of them:
1. to evaluate polynomials,
Applications of Factoring
There are many applications of the factored forms of
polynomials. Following are some of them:
1. to evaluate polynomials,
2. to determine the signs of the outputs,
Applications of Factoring
There are many applications of the factored forms of
polynomials. Following are some of them:
1. to evaluate polynomials,
2. to determine the signs of the outputs,
3. most importantly, to solve polynomial-equations.
Applications of Factoring
There are many applications of the factored forms of
polynomials. Following are some of them:
1. to evaluate polynomials,
2. to determine the signs of the outputs,
3. most importantly, to solve polynomial-equations.
Evaluating Polynomials
Applications of Factoring
There are many applications of the factored forms of
polynomials. Following are some of them:
1. to evaluate polynomials,
2. to determine the signs of the outputs,
3. most importantly, to solve polynomial-equations.
Evaluating Polynomials
Often it is easier to evaluate polynomials in the factored form.
Applications of Factoring
There are many applications of the factored forms of
polynomials. Following are some of them:
1. to evaluate polynomials,
2. to determine the signs of the outputs,
3. most importantly, to solve polynomial-equations.
Evaluating Polynomials
Example A. Evaluate x2 – 2x – 3 if x = 7
a. without factoring. b. by factoring it first.
Often it is easier to evaluate polynomials in the factored form.
Applications of Factoring
There are many applications of the factored forms of
polynomials. Following are some of them:
1. to evaluate polynomials,
2. to determine the signs of the outputs,
3. most importantly, to solve polynomial-equations.
Evaluating Polynomials
Example A. Evaluate x2 – 2x – 3 if x = 7
a. without factoring. b. by factoring it first.
We get
72 – 2(7) – 3
Often it is easier to evaluate polynomials in the factored form.
Applications of Factoring
There are many applications of the factored forms of
polynomials. Following are some of them:
1. to evaluate polynomials,
2. to determine the signs of the outputs,
3. most importantly, to solve polynomial-equations.
Evaluating Polynomials
Example A. Evaluate x2 – 2x – 3 if x = 7
a. without factoring. b. by factoring it first.
We get
72 – 2(7) – 3
= 49 – 14 – 3
Often it is easier to evaluate polynomials in the factored form.
Applications of Factoring
There are many applications of the factored forms of
polynomials. Following are some of them:
1. to evaluate polynomials,
2. to determine the signs of the outputs,
3. most importantly, to solve polynomial-equations.
Evaluating Polynomials
Example A. Evaluate x2 – 2x – 3 if x = 7
a. without factoring. b. by factoring it first.
We get
72 – 2(7) – 3
= 49 – 14 – 3
= 32
Often it is easier to evaluate polynomials in the factored form.
Applications of Factoring
There are many applications of the factored forms of
polynomials. Following are some of them:
1. to evaluate polynomials,
2. to determine the signs of the outputs,
3. most importantly, to solve polynomial-equations.
Evaluating Polynomials
Example A. Evaluate x2 – 2x – 3 if x = 7
a. without factoring. b. by factoring it first.
We get
72 – 2(7) – 3
= 49 – 14 – 3
= 32
x2 – 2x – 3 = (x – 3)(x+1)
Often it is easier to evaluate polynomials in the factored form.
Applications of Factoring
There are many applications of the factored forms of
polynomials. Following are some of them:
1. to evaluate polynomials,
2. to determine the signs of the outputs,
3. most importantly, to solve polynomial-equations.
Evaluating Polynomials
Example A. Evaluate x2 – 2x – 3 if x = 7
a. without factoring. b. by factoring it first.
We get
72 – 2(7) – 3
= 49 – 14 – 3
= 32
x2 – 2x – 3 = (x – 3)(x+1)
We get
(7 – 3)(7 + 1)
Often it is easier to evaluate polynomials in the factored form.
Applications of Factoring
There are many applications of the factored forms of
polynomials. Following are some of them:
1. to evaluate polynomials,
2. to determine the signs of the outputs,
3. most importantly, to solve polynomial-equations.
Evaluating Polynomials
Example A. Evaluate x2 – 2x – 3 if x = 7
a. without factoring. b. by factoring it first.
We get
72 – 2(7) – 3
= 49 – 14 – 3
= 32
x2 – 2x – 3 = (x – 3)(x+1)
We get
(7 – 3)(7 + 1)
= 4(8)
= 32
Often it is easier to evaluate polynomials in the factored form.
Applications of Factoring
There are many applications of the factored forms of
polynomials. Following are some of them:
1. to evaluate polynomials,
2. to determine the signs of the outputs,
3. most importantly, to solve polynomial-equations.
Evaluating Polynomials
Example A. Evaluate x2 – 2x – 3 if x = 7
a. without factoring. b. by factoring it first.
We get
72 – 2(7) – 3
= 49 – 14 – 3
= 32
x2 – 2x – 3 = (x – 3)(x+1)
We get
(7 – 3)(7 + 1)
= 4(8)
= 32
Often it is easier to evaluate polynomials in the factored form.
Example B. Evaluate 2x3 – 5x2 + 2x
for x = -2, -1, 3 by factoring it first.
Applications of Factoring
Example B. Evaluate 2x3 – 5x2 + 2x
for x = -2, -1, 3 by factoring it first.
2x3 – 5x2 + 2x = x(2x2 – 5x + 2)
Applications of Factoring
Example B. Evaluate 2x3 – 5x2 + 2x
for x = -2, -1, 3 by factoring it first.
2x3 – 5x2 + 2x = x(2x2 – 5x + 2)
= x(2x – 1)(x – 2)
Applications of Factoring
Example B. Evaluate 2x3 – 5x2 + 2x
for x = -2, -1, 3 by factoring it first.
2x3 – 5x2 + 2x = x(2x2 – 5x + 2)
= x(2x – 1)(x – 2)
For x = -2:
(-2)[2(-2) – 1] [(-2) – 2]
Applications of Factoring
Example B. Evaluate 2x3 – 5x2 + 2x
for x = -2, -1, 3 by factoring it first.
2x3 – 5x2 + 2x = x(2x2 – 5x + 2)
= x(2x – 1)(x – 2)
For x = -2:
(-2)[2(-2) – 1] [(-2) – 2] = -2 [-5] [-4]
Applications of Factoring
Example B. Evaluate 2x3 – 5x2 + 2x
for x = -2, -1, 3 by factoring it first.
2x3 – 5x2 + 2x = x(2x2 – 5x + 2)
= x(2x – 1)(x – 2)
For x = -2:
(-2)[2(-2) – 1] [(-2) – 2] = -2 [-5] [-4] = -40
Applications of Factoring
Example B. Evaluate 2x3 – 5x2 + 2x
for x = -2, -1, 3 by factoring it first.
2x3 – 5x2 + 2x = x(2x2 – 5x + 2)
= x(2x – 1)(x – 2)
For x = -2:
(-2)[2(-2) – 1] [(-2) – 2] = -2 [-5] [-4] = -40
For x = -1:
(-1)[2(-1) – 1] [(-1) – 2]
Applications of Factoring
Example B. Evaluate 2x3 – 5x2 + 2x
for x = -2, -1, 3 by factoring it first.
2x3 – 5x2 + 2x = x(2x2 – 5x + 2)
= x(2x – 1)(x – 2)
For x = -2:
(-2)[2(-2) – 1] [(-2) – 2] = -2 [-5] [-4] = -40
For x = -1:
(-1)[2(-1) – 1] [(-1) – 2] = -1 [-3] [-3]
Applications of Factoring
Example B. Evaluate 2x3 – 5x2 + 2x
for x = -2, -1, 3 by factoring it first.
2x3 – 5x2 + 2x = x(2x2 – 5x + 2)
= x(2x – 1)(x – 2)
For x = -2:
(-2)[2(-2) – 1] [(-2) – 2] = -2 [-5] [-4] = -40
For x = -1:
(-1)[2(-1) – 1] [(-1) – 2] = -1 [-3] [-3] = -9
Applications of Factoring
Example B. Evaluate 2x3 – 5x2 + 2x
for x = -2, -1, 3 by factoring it first.
2x3 – 5x2 + 2x = x(2x2 – 5x + 2)
= x(2x – 1)(x – 2)
For x = -2:
(-2)[2(-2) – 1] [(-2) – 2] = -2 [-5] [-4] = -40
For x = -1:
(-1)[2(-1) – 1] [(-1) – 2] = -1 [-3] [-3] = -9
For x = 3:
3 [2(3) – 1] [(3) – 2]
Applications of Factoring
Example B. Evaluate 2x3 – 5x2 + 2x
for x = -2, -1, 3 by factoring it first.
2x3 – 5x2 + 2x = x(2x2 – 5x + 2)
= x(2x – 1)(x – 2)
For x = -2:
(-2)[2(-2) – 1] [(-2) – 2] = -2 [-5] [-4] = -40
For x = -1:
(-1)[2(-1) – 1] [(-1) – 2] = -1 [-3] [-3] = -9
For x = 3:
3 [2(3) – 1] [(3) – 2] = 3 [5] [1] = 15
Applications of Factoring
Example B. Evaluate 2x3 – 5x2 + 2x
for x = -2, -1, 3 by factoring it first.
2x3 – 5x2 + 2x = x(2x2 – 5x + 2)
= x(2x – 1)(x – 2)
For x = -2:
(-2)[2(-2) – 1] [(-2) – 2] = -2 [-5] [-4] = -40
For x = -1:
(-1)[2(-1) – 1] [(-1) – 2] = -1 [-3] [-3] = -9
For x = 3:
3 [2(3) – 1] [(3) – 2] = 3 [5] [1] = 15
Applications of Factoring
Example B. Evaluate 2x3 – 5x2 + 2x
for x = -2, -1, 3 by factoring it first.
2x3 – 5x2 + 2x = x(2x2 – 5x + 2)
= x(2x – 1)(x – 2)
For x = -2:
(-2)[2(-2) – 1] [(-2) – 2] = -2 [-5] [-4] = -40
For x = -1:
(-1)[2(-1) – 1] [(-1) – 2] = -1 [-3] [-3] = -9
For x = 3:
3 [2(3) – 1] [(3) – 2] = 3 [5] [1] = 15
Applications of Factoring
Your turn: Double check these answers via the expanded form.
Example B. Evaluate 2x3 – 5x2 + 2x
for x = -2, -1, 3 by factoring it first.
2x3 – 5x2 + 2x = x(2x2 – 5x + 2)
= x(2x – 1)(x – 2)
For x = -2:
(-2)[2(-2) – 1] [(-2) – 2] = -2 [-5] [-4] = -40
For x = -1:
(-1)[2(-1) – 1] [(-1) – 2] = -1 [-3] [-3] = -9
For x = 3:
3 [2(3) – 1] [(3) – 2] = 3 [5] [1] = 15
Applications of Factoring
Determine the signs of the outputs
Your turn: Double check these answers via the expanded form.
Example B. Evaluate 2x3 – 5x2 + 2x
for x = -2, -1, 3 by factoring it first.
2x3 – 5x2 + 2x = x(2x2 – 5x + 2)
= x(2x – 1)(x – 2)
For x = -2:
(-2)[2(-2) – 1] [(-2) – 2] = -2 [-5] [-4] = -40
For x = -1:
(-1)[2(-1) – 1] [(-1) – 2] = -1 [-3] [-3] = -9
For x = 3:
3 [2(3) – 1] [(3) – 2] = 3 [5] [1] = 15
Applications of Factoring
Determine the signs of the outputs
Often we only want to know the sign of the output, i.e.
whether the output is positive or negative.
Your turn: Double check these answers via the expanded form.
Example B. Evaluate 2x3 – 5x2 + 2x
for x = -2, -1, 3 by factoring it first.
2x3 – 5x2 + 2x = x(2x2 – 5x + 2)
= x(2x – 1)(x – 2)
For x = -2:
(-2)[2(-2) – 1] [(-2) – 2] = -2 [-5] [-4] = -40
For x = -1:
(-1)[2(-1) – 1] [(-1) – 2] = -1 [-3] [-3] = -9
For x = 3:
3 [2(3) – 1] [(3) – 2] = 3 [5] [1] = 15
Applications of Factoring
Determine the signs of the outputs
Often we only want to know the sign of the output, i.e.
whether the output is positive or negative. It is easy to do this
using the factored form.
Your turn: Double check these answers via the expanded form.
Example C. Determine the outcome is + or – for x2 – 2x – 3
if x = -3/2, -1/2.
Applications of Factoring
Example C. Determine the outcome is + or – for x2 – 2x – 3
if x = -3/2, -1/2.
Factor x2 – 2x – 3 = (x – 3)(x + 1)
Applications of Factoring
Example C. Determine the outcome is + or – for x2 – 2x – 3
if x = -3/2, -1/2.
Factor x2 – 2x – 3 = (x – 3)(x + 1)
Hence for x = -3/2:
(-3/2 – 3)(-3/2 + 1)
Applications of Factoring
Example C. Determine the outcome is + or – for x2 – 2x – 3
if x = -3/2, -1/2.
Factor x2 – 2x – 3 = (x – 3)(x + 1)
Hence for x = -3/2:
(-3/2 – 3)(-3/2 + 1) is (–)(–) = + .
Applications of Factoring
Example C. Determine the outcome is + or – for x2 – 2x – 3
if x = -3/2, -1/2.
Factor x2 – 2x – 3 = (x – 3)(x + 1)
Hence for x = -3/2:
(-3/2 – 3)(-3/2 + 1) is (–)(–) = + . So the outcome is positive.
Applications of Factoring
Example C. Determine the outcome is + or – for x2 – 2x – 3
if x = -3/2, -1/2.
Factor x2 – 2x – 3 = (x – 3)(x + 1)
Hence for x = -3/2:
(-3/2 – 3)(-3/2 + 1) is (–)(–) = + . So the outcome is positive.
And for x = -1/2:
(-1/2 – 3)(-1/2 + 1)
Applications of Factoring
Example C. Determine the outcome is + or – for x2 – 2x – 3
if x = -3/2, -1/2.
Factor x2 – 2x – 3 = (x – 3)(x + 1)
Hence for x = -3/2:
(-3/2 – 3)(-3/2 + 1) is (–)(–) = + . So the outcome is positive.
And for x = -1/2:
(-1/2 – 3)(-1/2 + 1) is (–)(+) = – .
Applications of Factoring
Example C. Determine the outcome is + or – for x2 – 2x – 3
if x = -3/2, -1/2.
Factor x2 – 2x – 3 = (x – 3)(x + 1)
Hence for x = -3/2:
(-3/2 – 3)(-3/2 + 1) is (–)(–) = + . So the outcome is positive.
And for x = -1/2:
(-1/2 – 3)(-1/2 + 1) is (–)(+) = – . So the outcome is negative.
Applications of Factoring
Example C. Determine the outcome is + or – for x2 – 2x – 3
if x = -3/2, -1/2.
Factor x2 – 2x – 3 = (x – 3)(x + 1)
Hence for x = -3/2:
(-3/2 – 3)(-3/2 + 1) is (–)(–) = + . So the outcome is positive.
And for x = -1/2:
(-1/2 – 3)(-1/2 + 1) is (–)(+) = – . So the outcome is negative.
Applications of Factoring
Solving Equations
Example C. Determine the outcome is + or – for x2 – 2x – 3
if x = -3/2, -1/2.
Factor x2 – 2x – 3 = (x – 3)(x + 1)
Hence for x = -3/2:
(-3/2 – 3)(-3/2 + 1) is (–)(–) = + . So the outcome is positive.
And for x = -1/2:
(-1/2 – 3)(-1/2 + 1) is (–)(+) = – . So the outcome is negative.
Applications of Factoring
Solving Equations
The most important application for factoring is to solve
polynomial equations.
Example C. Determine the outcome is + or – for x2 – 2x – 3
if x = -3/2, -1/2.
Factor x2 – 2x – 3 = (x – 3)(x + 1)
Hence for x = -3/2:
(-3/2 – 3)(-3/2 + 1) is (–)(–) = + . So the outcome is positive.
And for x = -1/2:
(-1/2 – 3)(-1/2 + 1) is (–)(+) = – . So the outcome is negative.
Applications of Factoring
Solving Equations
The most important application for factoring is to solve
polynomial equations. These are equations of the form
polynomial = polynomial
Example C. Determine the outcome is + or – for x2 – 2x – 3
if x = -3/2, -1/2.
Factor x2 – 2x – 3 = (x – 3)(x + 1)
Hence for x = -3/2:
(-3/2 – 3)(-3/2 + 1) is (–)(–) = + . So the outcome is positive.
And for x = -1/2:
(-1/2 – 3)(-1/2 + 1) is (–)(+) = – . So the outcome is negative.
Applications of Factoring
Solving Equations
The most important application for factoring is to solve
polynomial equations. These are equations of the form
polynomial = polynomial
To solve these equations, we use the following obvious fact.
Example C. Determine the outcome is + or – for x2 – 2x – 3
if x = -3/2, -1/2.
Factor x2 – 2x – 3 = (x – 3)(x + 1)
Hence for x = -3/2:
(-3/2 – 3)(-3/2 + 1) is (–)(–) = + . So the outcome is positive.
And for x = -1/2:
(-1/2 – 3)(-1/2 + 1) is (–)(+) = – . So the outcome is negative.
Applications of Factoring
Solving Equations
The most important application for factoring is to solve
polynomial equations. These are equations of the form
polynomial = polynomial
To solve these equations, we use the following obvious fact.
Fact: If A*B = 0,
then either A = 0 or B = 0
Example C. Determine the outcome is + or – for x2 – 2x – 3
if x = -3/2, -1/2.
Factor x2 – 2x – 3 = (x – 3)(x + 1)
Hence for x = -3/2:
(-3/2 – 3)(-3/2 + 1) is (–)(–) = + . So the outcome is positive.
And for x = -1/2:
(-1/2 – 3)(-1/2 + 1) is (–)(+) = – . So the outcome is negative.
Applications of Factoring
Solving Equations
The most important application for factoring is to solve
polynomial equations. These are equations of the form
polynomial = polynomial
To solve these equations, we use the following obvious fact.
Fact: If A*B = 0,
then either A = 0 or B = 0
For example, if 3x = 0, then x must be equal to 0.
Example D.
a. If 3(x – 2) = 0,
Applications of Factoring
Example D.
a. If 3(x – 2) = 0, then (x – 2) = 0,
Applications of Factoring
Example D.
a. If 3(x – 2) = 0, then (x – 2) = 0, so x must be 2.
Applications of Factoring
Example D.
a. If 3(x – 2) = 0, then (x – 2) = 0, so x must be 2.
Applications of Factoring
b. If (x + 1)(x – 2) = 0,
Example D.
a. If 3(x – 2) = 0, then (x – 2) = 0, so x must be 2.
Applications of Factoring
b. If (x + 1)(x – 2) = 0,
then either (x + 1) = 0 or (x – 2) = 0,
Example D.
a. If 3(x – 2) = 0, then (x – 2) = 0, so x must be 2.
Applications of Factoring
b. If (x + 1)(x – 2) = 0,
then either (x + 1) = 0 or (x – 2) = 0,
x = –1
Example D.
a. If 3(x – 2) = 0, then (x – 2) = 0, so x must be 2.
Applications of Factoring
b. If (x + 1)(x – 2) = 0,
then either (x + 1) = 0 or (x – 2) = 0,
x = –1 or x = 2
Example D.
a. If 3(x – 2) = 0, then (x – 2) = 0, so x must be 2.
Applications of Factoring
To solve polynomial equation,
b. If (x + 1)(x – 2) = 0,
then either (x + 1) = 0 or (x – 2) = 0,
x = –1 or x = 2
Example D.
a. If 3(x – 2) = 0, then (x – 2) = 0, so x must be 2.
Applications of Factoring
To solve polynomial equation,
1. set one side of the equation to be 0, move all the terms to
the other side.
b. If (x + 1)(x – 2) = 0,
then either (x + 1) = 0 or (x – 2) = 0,
x = –1 or x = 2
Example D.
a. If 3(x – 2) = 0, then (x – 2) = 0, so x must be 2.
Applications of Factoring
To solve polynomial equation,
1. set one side of the equation to be 0, move all the terms to
the other side.
2. factor the polynomial,
b. If (x + 1)(x – 2) = 0,
then either (x + 1) = 0 or (x – 2) = 0,
x = –1 or x = 2
Example D.
a. If 3(x – 2) = 0, then (x – 2) = 0, so x must be 2.
Applications of Factoring
To solve polynomial equation,
1. set one side of the equation to be 0, move all the terms to
the other side.
2. factor the polynomial,
3. get the answers.
b. If (x + 1)(x – 2) = 0,
then either (x + 1) = 0 or (x – 2) = 0,
x = –1 or x = 2
Example D.
a. If 3(x – 2) = 0, then (x – 2) = 0, so x must be 2.
Applications of Factoring
To solve polynomial equation,
1. set one side of the equation to be 0, move all the terms to
the other side.
2. factor the polynomial,
3. get the answers.
b. If (x + 1)(x – 2) = 0,
then either (x + 1) = 0 or (x – 2) = 0,
x = –1 or x = 2
Example E. Solve for x
a. x2 – 2x – 3 = 0
Example D.
a. If 3(x – 2) = 0, then (x – 2) = 0, so x must be 2.
Applications of Factoring
To solve polynomial equation,
1. set one side of the equation to be 0, move all the terms to
the other side.
2. factor the polynomial,
3. get the answers.
b. If (x + 1)(x – 2) = 0,
then either (x + 1) = 0 or (x – 2) = 0,
x = –1 or x = 2
Example E. Solve for x
a. x2 – 2x – 3 = 0 Factor
(x – 3)(x + 1) = 0
Example D.
a. If 3(x – 2) = 0, then (x – 2) = 0, so x must be 2.
Applications of Factoring
To solve polynomial equation,
1. set one side of the equation to be 0, move all the terms to
the other side.
2. factor the polynomial,
3. get the answers.
b. If (x + 1)(x – 2) = 0,
then either (x + 1) = 0 or (x – 2) = 0,
x = –1 or x = 2
Example E. Solve for x
a. x2 – 2x – 3 = 0 Factor
(x – 3)(x + 1) = 0
There are two linear
x–factors. We may extract
one answer from each.
Example D.
a. If 3(x – 2) = 0, then (x – 2) = 0, so x must be 2.
Applications of Factoring
To solve polynomial equation,
1. set one side of the equation to be 0, move all the terms to
the other side.
2. factor the polynomial,
3. get the answers.
b. If (x + 1)(x – 2) = 0,
then either (x + 1) = 0 or (x – 2) = 0,
x = –1 or x = 2
Example E. Solve for x
a. x2 – 2x – 3 = 0 Factor
(x – 3)(x + 1) = 0
Hence x – 3 = 0 or x + 1 = 0
There are two linear
x–factors. We may extract
one answer from each.
Example D.
a. If 3(x – 2) = 0, then (x – 2) = 0, so x must be 2.
Applications of Factoring
To solve polynomial equation,
1. set one side of the equation to be 0, move all the terms to
the other side.
2. factor the polynomial,
3. get the answers.
b. If (x + 1)(x – 2) = 0,
then either (x + 1) = 0 or (x – 2) = 0,
x = –1 or x = 2
Example E. Solve for x
a. x2 – 2x – 3 = 0 Factor
(x – 3)(x + 1) = 0
Hence x – 3 = 0 or x + 1 = 0
x = 3
There are two linear
x–factors. We may extract
one answer from each.
Example D.
a. If 3(x – 2) = 0, then (x – 2) = 0, so x must be 2.
Applications of Factoring
To solve polynomial equation,
1. set one side of the equation to be 0, move all the terms to
the other side.
2. factor the polynomial,
3. get the answers.
b. If (x + 1)(x – 2) = 0,
then either (x + 1) = 0 or (x – 2) = 0,
x = –1 or x = 2
Example E. Solve for x
a. x2 – 2x – 3 = 0 Factor
(x – 3)(x + 1) = 0
Hence x – 3 = 0 or x + 1 = 0
x = 3 or x = -1
There are two linear
x–factors. We may extract
one answer from each.
b. 2x(x + 1) = 4x + 3(1 – x)
Applications of Factoring
b. 2x(x + 1) = 4x + 3(1 – x) Expand
2x2 + 2x = 4x + 3 – 3x
Applications of Factoring
b. 2x(x + 1) = 4x + 3(1 – x) Expand
2x2 + 2x = 4x + 3 – 3x
2x2 + 2x = x + 3
Applications of Factoring
b. 2x(x + 1) = 4x + 3(1 – x) Expand
2x2 + 2x = 4x + 3 – 3x
2x2 + 2x = x + 3 Set one side 0
2x2 + 2x – x – 3 = 0
Applications of Factoring
b. 2x(x + 1) = 4x + 3(1 – x) Expand
2x2 + 2x = 4x + 3 – 3x
2x2 + 2x = x + 3 Set one side 0
2x2 + 2x – x – 3 = 0
2x2 + x – 3 = 0
Applications of Factoring
b. 2x(x + 1) = 4x + 3(1 – x) Expand
2x2 + 2x = 4x + 3 – 3x
2x2 + 2x = x + 3 Set one side 0
2x2 + 2x – x – 3 = 0
2x2 + x – 3 = 0 Factor
(2x + 3)(x – 1) = 0
Applications of Factoring
b. 2x(x + 1) = 4x + 3(1 – x) Expand
2x2 + 2x = 4x + 3 – 3x
2x2 + 2x = x + 3 Set one side 0
2x2 + 2x – x – 3 = 0
2x2 + x – 3 = 0 Factor
(2x + 3)(x – 1) = 0 Get the answers
2x + 3 = 0
Applications of Factoring
or x – 1 = 0
b. 2x(x + 1) = 4x + 3(1 – x) Expand
2x2 + 2x = 4x + 3 – 3x
2x2 + 2x = x + 3 Set one side 0
2x2 + 2x – x – 3 = 0
2x2 + x – 3 = 0 Factor
(2x + 3)(x – 1) = 0 Get the answers
2x + 3 = 0
2x = -3
Applications of Factoring
or x – 1 = 0
b. 2x(x + 1) = 4x + 3(1 – x) Expand
2x2 + 2x = 4x + 3 – 3x
2x2 + 2x = x + 3 Set one side 0
2x2 + 2x – x – 3 = 0
2x2 + x – 3 = 0 Factor
(2x + 3)(x – 1) = 0 Get the answers
2x + 3 = 0
2x = -3
x = -3/2
Applications of Factoring
or x – 1 = 0
b. 2x(x + 1) = 4x + 3(1 – x) Expand
2x2 + 2x = 4x + 3 – 3x
2x2 + 2x = x + 3 Set one side 0
2x2 + 2x – x – 3 = 0
2x2 + x – 3 = 0 Factor
(2x + 3)(x – 1) = 0 Get the answers
2x + 3 = 0
2x = -3
x = -3/2
Applications of Factoring
or x – 1 = 0
x = 1
b. 2x(x + 1) = 4x + 3(1 – x) Expand
2x2 + 2x = 4x + 3 – 3x
2x2 + 2x = x + 3 Set one side 0
2x2 + 2x – x – 3 = 0
2x2 + x – 3 = 0 Factor
(2x + 3)(x – 1) = 0 Get the answers
2x + 3 = 0
2x = -3
x = -3/2
Applications of Factoring
or x – 1 = 0
x = 1
c. 8x(x2 – 1) = 10x
b. 2x(x + 1) = 4x + 3(1 – x) Expand
2x2 + 2x = 4x + 3 – 3x
2x2 + 2x = x + 3 Set one side 0
2x2 + 2x – x – 3 = 0
2x2 + x – 3 = 0 Factor
(2x + 3)(x – 1) = 0 Get the answers
2x + 3 = 0
2x = -3
x = -3/2
Applications of Factoring
or x – 1 = 0
x = 1
c. 8x(x2 – 1) = 10x Expand
8x3 – 8x = 10x
b. 2x(x + 1) = 4x + 3(1 – x) Expand
2x2 + 2x = 4x + 3 – 3x
2x2 + 2x = x + 3 Set one side 0
2x2 + 2x – x – 3 = 0
2x2 + x – 3 = 0 Factor
(2x + 3)(x – 1) = 0 Get the answers
2x + 3 = 0
2x = -3
x = -3/2
Applications of Factoring
or x – 1 = 0
x = 1
c. 8x(x2 – 1) = 10x Expand
8x3 – 8x = 10x Set one side 0
8x3 – 8x – 10x = 0
b. 2x(x + 1) = 4x + 3(1 – x) Expand
2x2 + 2x = 4x + 3 – 3x
2x2 + 2x = x + 3 Set one side 0
2x2 + 2x – x – 3 = 0
2x2 + x – 3 = 0 Factor
(2x + 3)(x – 1) = 0 Get the answers
2x + 3 = 0
2x = -3
x = -3/2
Applications of Factoring
or x – 1 = 0
x = 1
c. 8x(x2 – 1) = 10x Expand
8x3 – 8x = 10x Set one side 0
8x3 – 8x – 10x = 0
8x3 – 18x = 0
b. 2x(x + 1) = 4x + 3(1 – x) Expand
2x2 + 2x = 4x + 3 – 3x
2x2 + 2x = x + 3 Set one side 0
2x2 + 2x – x – 3 = 0
2x2 + x – 3 = 0 Factor
(2x + 3)(x – 1) = 0 Get the answers
2x + 3 = 0
2x = -3
x = -3/2
Applications of Factoring
or x – 1 = 0
x = 1
c. 8x(x2 – 1) = 10x Expand
8x3 – 8x = 10x Set one side 0
8x3 – 8x – 10x = 0
8x3 – 18x = 0 Factor
2x(2x + 3)(2x – 3) = 0
b. 2x(x + 1) = 4x + 3(1 – x) Expand
2x2 + 2x = 4x + 3 – 3x
2x2 + 2x = x + 3 Set one side 0
2x2 + 2x – x – 3 = 0
2x2 + x – 3 = 0 Factor
(2x + 3)(x – 1) = 0 Get the answers
2x + 3 = 0
2x = -3
x = -3/2
Applications of Factoring
or x – 1 = 0
x = 1
c. 8x(x2 – 1) = 10x Expand
8x3 – 8x = 10x Set one side 0
8x3 – 8x – 10x = 0
8x3 – 18x = 0 Factor
2x(2x + 3)(2x – 3) = 0
There are three linear
x–factors. We may extract
one answer from each.
b. 2x(x + 1) = 4x + 3(1 – x) Expand
2x2 + 2x = 4x + 3 – 3x
2x2 + 2x = x + 3 Set one side 0
2x2 + 2x – x – 3 = 0
2x2 + x – 3 = 0 Factor
(2x + 3)(x – 1) = 0 Get the answers
2x + 3 = 0
2x = -3
x = -3/2
Applications of Factoring
or x – 1 = 0
x = 1
c. 8x(x2 – 1) = 10x Expand
8x3 – 8x = 10x Set one side 0
8x3 – 8x – 10x = 0
8x3 – 18x = 0 Factor
2x(2x + 3)(2x – 3) = 0
x = 0
There are three linear
x–factors. We may extract
one answer from each.
b. 2x(x + 1) = 4x + 3(1 – x) Expand
2x2 + 2x = 4x + 3 – 3x
2x2 + 2x = x + 3 Set one side 0
2x2 + 2x – x – 3 = 0
2x2 + x – 3 = 0 Factor
(2x + 3)(x – 1) = 0 Get the answers
2x + 3 = 0
2x = -3
x = -3/2
Applications of Factoring
or x – 1 = 0
x = 1
c. 8x(x2 – 1) = 10x Expand
8x3 – 8x = 10x Set one side 0
8x3 – 8x – 10x = 0
8x3 – 18x = 0 Factor
2x(2x + 3)(2x – 3) = 0
x = 0 or 2x + 3 = 0
There are three linear
x–factors. We may extract
one answer from each.
b. 2x(x + 1) = 4x + 3(1 – x) Expand
2x2 + 2x = 4x + 3 – 3x
2x2 + 2x = x + 3 Set one side 0
2x2 + 2x – x – 3 = 0
2x2 + x – 3 = 0 Factor
(2x + 3)(x – 1) = 0 Get the answers
2x + 3 = 0
2x = -3
x = -3/2
Applications of Factoring
or x – 1 = 0
x = 1
c. 8x(x2 – 1) = 10x Expand
8x3 – 8x = 10x Set one side 0
8x3 – 8x – 10x = 0
8x3 – 18x = 0 Factor
2x(2x + 3)(2x – 3) = 0
x = 0 or 2x + 3 = 0 or 2x – 3 = 0
There are three linear
x–factors. We may extract
one answer from each.
b. 2x(x + 1) = 4x + 3(1 – x) Expand
2x2 + 2x = 4x + 3 – 3x
2x2 + 2x = x + 3 Set one side 0
2x2 + 2x – x – 3 = 0
2x2 + x – 3 = 0 Factor
(2x + 3)(x – 1) = 0 Get the answers
2x + 3 = 0
2x = -3
x = -3/2
Applications of Factoring
or x – 1 = 0
x = 1
c. 8x(x2 – 1) = 10x Expand
8x3 – 8x = 10x Set one side 0
8x3 – 8x – 10x = 0
8x3 – 18x = 0 Factor
2x(2x + 3)(2x – 3) = 0
x = 0 or 2x + 3 = 0 or 2x – 3 = 0
2x = -3
There are three linear
x–factors. We may extract
one answer from each.
b. 2x(x + 1) = 4x + 3(1 – x) Expand
2x2 + 2x = 4x + 3 – 3x
2x2 + 2x = x + 3 Set one side 0
2x2 + 2x – x – 3 = 0
2x2 + x – 3 = 0 Factor
(2x + 3)(x – 1) = 0 Get the answers
2x + 3 = 0
2x = -3
x = -3/2
Applications of Factoring
or x – 1 = 0
x = 1
c. 8x(x2 – 1) = 10x Expand
8x3 – 8x = 10x Set one side 0
8x3 – 8x – 10x = 0
8x3 – 18x = 0 Factor
2x(2x + 3)(2x – 3) = 0
x = 0 or 2x + 3 = 0 or 2x – 3 = 0
2x = -3
x = -3/2
There are three linear
x–factors. We may extract
one answer from each.
b. 2x(x + 1) = 4x + 3(1 – x) Expand
2x2 + 2x = 4x + 3 – 3x
2x2 + 2x = x + 3 Set one side 0
2x2 + 2x – x – 3 = 0
2x2 + x – 3 = 0 Factor
(2x + 3)(x – 1) = 0 Get the answers
2x + 3 = 0
2x = -3
x = -3/2
Applications of Factoring
or x – 1 = 0
x = 1
c. 8x(x2 – 1) = 10x Expand
8x3 – 8x = 10x Set one side 0
8x3 – 8x – 10x = 0
8x3 – 18x = 0 Factor
2x(2x + 3)(2x – 3) = 0
x = 0 or 2x + 3 = 0 or 2x – 3 = 0
2x = -3 2x = 3
x = -3/2
There are three linear
x–factors. We may extract
one answer from each.
b. 2x(x + 1) = 4x + 3(1 – x) Expand
2x2 + 2x = 4x + 3 – 3x
2x2 + 2x = x + 3 Set one side 0
2x2 + 2x – x – 3 = 0
2x2 + x – 3 = 0 Factor
(2x + 3)(x – 1) = 0 Get the answers
2x + 3 = 0
2x = -3
x = -3/2
Applications of Factoring
or x – 1 = 0
x = 1
c. 8x(x2 – 1) = 10x Expand
8x3 – 8x = 10x Set one side 0
8x3 – 8x – 10x = 0
8x3 – 18x = 0 Factor
2x(2x + 3)(2x – 3) = 0
x = 0 or 2x + 3 = 0 or 2x – 3 = 0
2x = -3 2x = 3
x = -3/2 x = 3/2
There are three linear
x–factors. We may extract
one answer from each.
Exercise A. Use the factored form to evaluate the following
expressions with the given input values.
Applications of Factoring
1. x2 – 3x – 4, x = –2, 3, 5 2. x2 – 2x – 15, x = –1, 4, 7
3. x2 – 2x – 1, x = ½ ,–2, –½ 4. x3 – 2x2, x = –2, 2, 4
5. x3 – 4x2 – 5x, x = –4, 2, 6 6. 2x3 – 3x2 + x, x = –3, 3, 5
B. Determine if the output is positive or negative using the
factored form.
7. x2 – 3x – 4, x = –2½, –2/3, 2½, 5¼
8. –x2 + 2x + 8, x = –2½, –2/3, 2½, 5¼
9. x3 – 2x2 – 8x, x = –4½, –3/4, ¼, 6¼,
11. 4x2 – x3, x = –1.22, 0.87, 3.22, 4.01
12. 18x – 2x3, x = –4.90, –2.19, 1.53, 3.01
10. 2x3 – 3x2 – 2x, x = –2½, –3/4, ¼, 3¼,
C. Solve the following equations. Check the answers.
Applications of Factoring
18. x2 – 3x = 10 20. x(x – 2) = 24 21. 2x2 = 3(x + 1) – 1
28. x3 – 2x2 = 0
22. x2 = 4
25. 2x(x – 3) + 4 = 2x – 4
29. x3 – 2x2 – 8x = 0
31. 4x2 = x3
30. 2x2(x – 3) = –4x
26. x(x – 3) + x + 6 = 2x2 + 3x
13. x2 – 3x – 4 = 0 14. x2 – 2x – 15 = 0 15. x2 + 7x + 12 = 0
16. –x2 – 2x + 8 = 0 17. 9 – x2 = 0 18. 2x2 – x – 1 = 0
27. x(x + 4) + 9 = 2(2 – x)
23. 8x2 = 2 24. 27x2 – 12 = 0
32. 4x = x3 33. 4x2 = x4
34. 7x2 = –4x3 – 3x 35. 5 = (x + 2)(2x + 1)
36. (x – 1)2 = (x + 1)2 – 4 37. (x + 1)2 = x2 + (x – 1)2
38. (x + 2)2 – (x + 1)2= x2 39. (x + 3)2 – (x + 2)2 = (x + 1)2

11 applications of factoring

  • 1.
  • 2.
    Applications of Factoring Thereare many applications of the factored forms of polynomials.
  • 3.
    Applications of Factoring Thereare many applications of the factored forms of polynomials. Following are some of them:
  • 4.
    Applications of Factoring Thereare many applications of the factored forms of polynomials. Following are some of them: 1. to evaluate polynomials,
  • 5.
    Applications of Factoring Thereare many applications of the factored forms of polynomials. Following are some of them: 1. to evaluate polynomials, 2. to determine the signs of the outputs,
  • 6.
    Applications of Factoring Thereare many applications of the factored forms of polynomials. Following are some of them: 1. to evaluate polynomials, 2. to determine the signs of the outputs, 3. most importantly, to solve polynomial-equations.
  • 7.
    Applications of Factoring Thereare many applications of the factored forms of polynomials. Following are some of them: 1. to evaluate polynomials, 2. to determine the signs of the outputs, 3. most importantly, to solve polynomial-equations. Evaluating Polynomials
  • 8.
    Applications of Factoring Thereare many applications of the factored forms of polynomials. Following are some of them: 1. to evaluate polynomials, 2. to determine the signs of the outputs, 3. most importantly, to solve polynomial-equations. Evaluating Polynomials Often it is easier to evaluate polynomials in the factored form.
  • 9.
    Applications of Factoring Thereare many applications of the factored forms of polynomials. Following are some of them: 1. to evaluate polynomials, 2. to determine the signs of the outputs, 3. most importantly, to solve polynomial-equations. Evaluating Polynomials Example A. Evaluate x2 – 2x – 3 if x = 7 a. without factoring. b. by factoring it first. Often it is easier to evaluate polynomials in the factored form.
  • 10.
    Applications of Factoring Thereare many applications of the factored forms of polynomials. Following are some of them: 1. to evaluate polynomials, 2. to determine the signs of the outputs, 3. most importantly, to solve polynomial-equations. Evaluating Polynomials Example A. Evaluate x2 – 2x – 3 if x = 7 a. without factoring. b. by factoring it first. We get 72 – 2(7) – 3 Often it is easier to evaluate polynomials in the factored form.
  • 11.
    Applications of Factoring Thereare many applications of the factored forms of polynomials. Following are some of them: 1. to evaluate polynomials, 2. to determine the signs of the outputs, 3. most importantly, to solve polynomial-equations. Evaluating Polynomials Example A. Evaluate x2 – 2x – 3 if x = 7 a. without factoring. b. by factoring it first. We get 72 – 2(7) – 3 = 49 – 14 – 3 Often it is easier to evaluate polynomials in the factored form.
  • 12.
    Applications of Factoring Thereare many applications of the factored forms of polynomials. Following are some of them: 1. to evaluate polynomials, 2. to determine the signs of the outputs, 3. most importantly, to solve polynomial-equations. Evaluating Polynomials Example A. Evaluate x2 – 2x – 3 if x = 7 a. without factoring. b. by factoring it first. We get 72 – 2(7) – 3 = 49 – 14 – 3 = 32 Often it is easier to evaluate polynomials in the factored form.
  • 13.
    Applications of Factoring Thereare many applications of the factored forms of polynomials. Following are some of them: 1. to evaluate polynomials, 2. to determine the signs of the outputs, 3. most importantly, to solve polynomial-equations. Evaluating Polynomials Example A. Evaluate x2 – 2x – 3 if x = 7 a. without factoring. b. by factoring it first. We get 72 – 2(7) – 3 = 49 – 14 – 3 = 32 x2 – 2x – 3 = (x – 3)(x+1) Often it is easier to evaluate polynomials in the factored form.
  • 14.
    Applications of Factoring Thereare many applications of the factored forms of polynomials. Following are some of them: 1. to evaluate polynomials, 2. to determine the signs of the outputs, 3. most importantly, to solve polynomial-equations. Evaluating Polynomials Example A. Evaluate x2 – 2x – 3 if x = 7 a. without factoring. b. by factoring it first. We get 72 – 2(7) – 3 = 49 – 14 – 3 = 32 x2 – 2x – 3 = (x – 3)(x+1) We get (7 – 3)(7 + 1) Often it is easier to evaluate polynomials in the factored form.
  • 15.
    Applications of Factoring Thereare many applications of the factored forms of polynomials. Following are some of them: 1. to evaluate polynomials, 2. to determine the signs of the outputs, 3. most importantly, to solve polynomial-equations. Evaluating Polynomials Example A. Evaluate x2 – 2x – 3 if x = 7 a. without factoring. b. by factoring it first. We get 72 – 2(7) – 3 = 49 – 14 – 3 = 32 x2 – 2x – 3 = (x – 3)(x+1) We get (7 – 3)(7 + 1) = 4(8) = 32 Often it is easier to evaluate polynomials in the factored form.
  • 16.
    Applications of Factoring Thereare many applications of the factored forms of polynomials. Following are some of them: 1. to evaluate polynomials, 2. to determine the signs of the outputs, 3. most importantly, to solve polynomial-equations. Evaluating Polynomials Example A. Evaluate x2 – 2x – 3 if x = 7 a. without factoring. b. by factoring it first. We get 72 – 2(7) – 3 = 49 – 14 – 3 = 32 x2 – 2x – 3 = (x – 3)(x+1) We get (7 – 3)(7 + 1) = 4(8) = 32 Often it is easier to evaluate polynomials in the factored form.
  • 17.
    Example B. Evaluate2x3 – 5x2 + 2x for x = -2, -1, 3 by factoring it first. Applications of Factoring
  • 18.
    Example B. Evaluate2x3 – 5x2 + 2x for x = -2, -1, 3 by factoring it first. 2x3 – 5x2 + 2x = x(2x2 – 5x + 2) Applications of Factoring
  • 19.
    Example B. Evaluate2x3 – 5x2 + 2x for x = -2, -1, 3 by factoring it first. 2x3 – 5x2 + 2x = x(2x2 – 5x + 2) = x(2x – 1)(x – 2) Applications of Factoring
  • 20.
    Example B. Evaluate2x3 – 5x2 + 2x for x = -2, -1, 3 by factoring it first. 2x3 – 5x2 + 2x = x(2x2 – 5x + 2) = x(2x – 1)(x – 2) For x = -2: (-2)[2(-2) – 1] [(-2) – 2] Applications of Factoring
  • 21.
    Example B. Evaluate2x3 – 5x2 + 2x for x = -2, -1, 3 by factoring it first. 2x3 – 5x2 + 2x = x(2x2 – 5x + 2) = x(2x – 1)(x – 2) For x = -2: (-2)[2(-2) – 1] [(-2) – 2] = -2 [-5] [-4] Applications of Factoring
  • 22.
    Example B. Evaluate2x3 – 5x2 + 2x for x = -2, -1, 3 by factoring it first. 2x3 – 5x2 + 2x = x(2x2 – 5x + 2) = x(2x – 1)(x – 2) For x = -2: (-2)[2(-2) – 1] [(-2) – 2] = -2 [-5] [-4] = -40 Applications of Factoring
  • 23.
    Example B. Evaluate2x3 – 5x2 + 2x for x = -2, -1, 3 by factoring it first. 2x3 – 5x2 + 2x = x(2x2 – 5x + 2) = x(2x – 1)(x – 2) For x = -2: (-2)[2(-2) – 1] [(-2) – 2] = -2 [-5] [-4] = -40 For x = -1: (-1)[2(-1) – 1] [(-1) – 2] Applications of Factoring
  • 24.
    Example B. Evaluate2x3 – 5x2 + 2x for x = -2, -1, 3 by factoring it first. 2x3 – 5x2 + 2x = x(2x2 – 5x + 2) = x(2x – 1)(x – 2) For x = -2: (-2)[2(-2) – 1] [(-2) – 2] = -2 [-5] [-4] = -40 For x = -1: (-1)[2(-1) – 1] [(-1) – 2] = -1 [-3] [-3] Applications of Factoring
  • 25.
    Example B. Evaluate2x3 – 5x2 + 2x for x = -2, -1, 3 by factoring it first. 2x3 – 5x2 + 2x = x(2x2 – 5x + 2) = x(2x – 1)(x – 2) For x = -2: (-2)[2(-2) – 1] [(-2) – 2] = -2 [-5] [-4] = -40 For x = -1: (-1)[2(-1) – 1] [(-1) – 2] = -1 [-3] [-3] = -9 Applications of Factoring
  • 26.
    Example B. Evaluate2x3 – 5x2 + 2x for x = -2, -1, 3 by factoring it first. 2x3 – 5x2 + 2x = x(2x2 – 5x + 2) = x(2x – 1)(x – 2) For x = -2: (-2)[2(-2) – 1] [(-2) – 2] = -2 [-5] [-4] = -40 For x = -1: (-1)[2(-1) – 1] [(-1) – 2] = -1 [-3] [-3] = -9 For x = 3: 3 [2(3) – 1] [(3) – 2] Applications of Factoring
  • 27.
    Example B. Evaluate2x3 – 5x2 + 2x for x = -2, -1, 3 by factoring it first. 2x3 – 5x2 + 2x = x(2x2 – 5x + 2) = x(2x – 1)(x – 2) For x = -2: (-2)[2(-2) – 1] [(-2) – 2] = -2 [-5] [-4] = -40 For x = -1: (-1)[2(-1) – 1] [(-1) – 2] = -1 [-3] [-3] = -9 For x = 3: 3 [2(3) – 1] [(3) – 2] = 3 [5] [1] = 15 Applications of Factoring
  • 28.
    Example B. Evaluate2x3 – 5x2 + 2x for x = -2, -1, 3 by factoring it first. 2x3 – 5x2 + 2x = x(2x2 – 5x + 2) = x(2x – 1)(x – 2) For x = -2: (-2)[2(-2) – 1] [(-2) – 2] = -2 [-5] [-4] = -40 For x = -1: (-1)[2(-1) – 1] [(-1) – 2] = -1 [-3] [-3] = -9 For x = 3: 3 [2(3) – 1] [(3) – 2] = 3 [5] [1] = 15 Applications of Factoring
  • 29.
    Example B. Evaluate2x3 – 5x2 + 2x for x = -2, -1, 3 by factoring it first. 2x3 – 5x2 + 2x = x(2x2 – 5x + 2) = x(2x – 1)(x – 2) For x = -2: (-2)[2(-2) – 1] [(-2) – 2] = -2 [-5] [-4] = -40 For x = -1: (-1)[2(-1) – 1] [(-1) – 2] = -1 [-3] [-3] = -9 For x = 3: 3 [2(3) – 1] [(3) – 2] = 3 [5] [1] = 15 Applications of Factoring Your turn: Double check these answers via the expanded form.
  • 30.
    Example B. Evaluate2x3 – 5x2 + 2x for x = -2, -1, 3 by factoring it first. 2x3 – 5x2 + 2x = x(2x2 – 5x + 2) = x(2x – 1)(x – 2) For x = -2: (-2)[2(-2) – 1] [(-2) – 2] = -2 [-5] [-4] = -40 For x = -1: (-1)[2(-1) – 1] [(-1) – 2] = -1 [-3] [-3] = -9 For x = 3: 3 [2(3) – 1] [(3) – 2] = 3 [5] [1] = 15 Applications of Factoring Determine the signs of the outputs Your turn: Double check these answers via the expanded form.
  • 31.
    Example B. Evaluate2x3 – 5x2 + 2x for x = -2, -1, 3 by factoring it first. 2x3 – 5x2 + 2x = x(2x2 – 5x + 2) = x(2x – 1)(x – 2) For x = -2: (-2)[2(-2) – 1] [(-2) – 2] = -2 [-5] [-4] = -40 For x = -1: (-1)[2(-1) – 1] [(-1) – 2] = -1 [-3] [-3] = -9 For x = 3: 3 [2(3) – 1] [(3) – 2] = 3 [5] [1] = 15 Applications of Factoring Determine the signs of the outputs Often we only want to know the sign of the output, i.e. whether the output is positive or negative. Your turn: Double check these answers via the expanded form.
  • 32.
    Example B. Evaluate2x3 – 5x2 + 2x for x = -2, -1, 3 by factoring it first. 2x3 – 5x2 + 2x = x(2x2 – 5x + 2) = x(2x – 1)(x – 2) For x = -2: (-2)[2(-2) – 1] [(-2) – 2] = -2 [-5] [-4] = -40 For x = -1: (-1)[2(-1) – 1] [(-1) – 2] = -1 [-3] [-3] = -9 For x = 3: 3 [2(3) – 1] [(3) – 2] = 3 [5] [1] = 15 Applications of Factoring Determine the signs of the outputs Often we only want to know the sign of the output, i.e. whether the output is positive or negative. It is easy to do this using the factored form. Your turn: Double check these answers via the expanded form.
  • 33.
    Example C. Determinethe outcome is + or – for x2 – 2x – 3 if x = -3/2, -1/2. Applications of Factoring
  • 34.
    Example C. Determinethe outcome is + or – for x2 – 2x – 3 if x = -3/2, -1/2. Factor x2 – 2x – 3 = (x – 3)(x + 1) Applications of Factoring
  • 35.
    Example C. Determinethe outcome is + or – for x2 – 2x – 3 if x = -3/2, -1/2. Factor x2 – 2x – 3 = (x – 3)(x + 1) Hence for x = -3/2: (-3/2 – 3)(-3/2 + 1) Applications of Factoring
  • 36.
    Example C. Determinethe outcome is + or – for x2 – 2x – 3 if x = -3/2, -1/2. Factor x2 – 2x – 3 = (x – 3)(x + 1) Hence for x = -3/2: (-3/2 – 3)(-3/2 + 1) is (–)(–) = + . Applications of Factoring
  • 37.
    Example C. Determinethe outcome is + or – for x2 – 2x – 3 if x = -3/2, -1/2. Factor x2 – 2x – 3 = (x – 3)(x + 1) Hence for x = -3/2: (-3/2 – 3)(-3/2 + 1) is (–)(–) = + . So the outcome is positive. Applications of Factoring
  • 38.
    Example C. Determinethe outcome is + or – for x2 – 2x – 3 if x = -3/2, -1/2. Factor x2 – 2x – 3 = (x – 3)(x + 1) Hence for x = -3/2: (-3/2 – 3)(-3/2 + 1) is (–)(–) = + . So the outcome is positive. And for x = -1/2: (-1/2 – 3)(-1/2 + 1) Applications of Factoring
  • 39.
    Example C. Determinethe outcome is + or – for x2 – 2x – 3 if x = -3/2, -1/2. Factor x2 – 2x – 3 = (x – 3)(x + 1) Hence for x = -3/2: (-3/2 – 3)(-3/2 + 1) is (–)(–) = + . So the outcome is positive. And for x = -1/2: (-1/2 – 3)(-1/2 + 1) is (–)(+) = – . Applications of Factoring
  • 40.
    Example C. Determinethe outcome is + or – for x2 – 2x – 3 if x = -3/2, -1/2. Factor x2 – 2x – 3 = (x – 3)(x + 1) Hence for x = -3/2: (-3/2 – 3)(-3/2 + 1) is (–)(–) = + . So the outcome is positive. And for x = -1/2: (-1/2 – 3)(-1/2 + 1) is (–)(+) = – . So the outcome is negative. Applications of Factoring
  • 41.
    Example C. Determinethe outcome is + or – for x2 – 2x – 3 if x = -3/2, -1/2. Factor x2 – 2x – 3 = (x – 3)(x + 1) Hence for x = -3/2: (-3/2 – 3)(-3/2 + 1) is (–)(–) = + . So the outcome is positive. And for x = -1/2: (-1/2 – 3)(-1/2 + 1) is (–)(+) = – . So the outcome is negative. Applications of Factoring Solving Equations
  • 42.
    Example C. Determinethe outcome is + or – for x2 – 2x – 3 if x = -3/2, -1/2. Factor x2 – 2x – 3 = (x – 3)(x + 1) Hence for x = -3/2: (-3/2 – 3)(-3/2 + 1) is (–)(–) = + . So the outcome is positive. And for x = -1/2: (-1/2 – 3)(-1/2 + 1) is (–)(+) = – . So the outcome is negative. Applications of Factoring Solving Equations The most important application for factoring is to solve polynomial equations.
  • 43.
    Example C. Determinethe outcome is + or – for x2 – 2x – 3 if x = -3/2, -1/2. Factor x2 – 2x – 3 = (x – 3)(x + 1) Hence for x = -3/2: (-3/2 – 3)(-3/2 + 1) is (–)(–) = + . So the outcome is positive. And for x = -1/2: (-1/2 – 3)(-1/2 + 1) is (–)(+) = – . So the outcome is negative. Applications of Factoring Solving Equations The most important application for factoring is to solve polynomial equations. These are equations of the form polynomial = polynomial
  • 44.
    Example C. Determinethe outcome is + or – for x2 – 2x – 3 if x = -3/2, -1/2. Factor x2 – 2x – 3 = (x – 3)(x + 1) Hence for x = -3/2: (-3/2 – 3)(-3/2 + 1) is (–)(–) = + . So the outcome is positive. And for x = -1/2: (-1/2 – 3)(-1/2 + 1) is (–)(+) = – . So the outcome is negative. Applications of Factoring Solving Equations The most important application for factoring is to solve polynomial equations. These are equations of the form polynomial = polynomial To solve these equations, we use the following obvious fact.
  • 45.
    Example C. Determinethe outcome is + or – for x2 – 2x – 3 if x = -3/2, -1/2. Factor x2 – 2x – 3 = (x – 3)(x + 1) Hence for x = -3/2: (-3/2 – 3)(-3/2 + 1) is (–)(–) = + . So the outcome is positive. And for x = -1/2: (-1/2 – 3)(-1/2 + 1) is (–)(+) = – . So the outcome is negative. Applications of Factoring Solving Equations The most important application for factoring is to solve polynomial equations. These are equations of the form polynomial = polynomial To solve these equations, we use the following obvious fact. Fact: If A*B = 0, then either A = 0 or B = 0
  • 46.
    Example C. Determinethe outcome is + or – for x2 – 2x – 3 if x = -3/2, -1/2. Factor x2 – 2x – 3 = (x – 3)(x + 1) Hence for x = -3/2: (-3/2 – 3)(-3/2 + 1) is (–)(–) = + . So the outcome is positive. And for x = -1/2: (-1/2 – 3)(-1/2 + 1) is (–)(+) = – . So the outcome is negative. Applications of Factoring Solving Equations The most important application for factoring is to solve polynomial equations. These are equations of the form polynomial = polynomial To solve these equations, we use the following obvious fact. Fact: If A*B = 0, then either A = 0 or B = 0 For example, if 3x = 0, then x must be equal to 0.
  • 47.
    Example D. a. If3(x – 2) = 0, Applications of Factoring
  • 48.
    Example D. a. If3(x – 2) = 0, then (x – 2) = 0, Applications of Factoring
  • 49.
    Example D. a. If3(x – 2) = 0, then (x – 2) = 0, so x must be 2. Applications of Factoring
  • 50.
    Example D. a. If3(x – 2) = 0, then (x – 2) = 0, so x must be 2. Applications of Factoring b. If (x + 1)(x – 2) = 0,
  • 51.
    Example D. a. If3(x – 2) = 0, then (x – 2) = 0, so x must be 2. Applications of Factoring b. If (x + 1)(x – 2) = 0, then either (x + 1) = 0 or (x – 2) = 0,
  • 52.
    Example D. a. If3(x – 2) = 0, then (x – 2) = 0, so x must be 2. Applications of Factoring b. If (x + 1)(x – 2) = 0, then either (x + 1) = 0 or (x – 2) = 0, x = –1
  • 53.
    Example D. a. If3(x – 2) = 0, then (x – 2) = 0, so x must be 2. Applications of Factoring b. If (x + 1)(x – 2) = 0, then either (x + 1) = 0 or (x – 2) = 0, x = –1 or x = 2
  • 54.
    Example D. a. If3(x – 2) = 0, then (x – 2) = 0, so x must be 2. Applications of Factoring To solve polynomial equation, b. If (x + 1)(x – 2) = 0, then either (x + 1) = 0 or (x – 2) = 0, x = –1 or x = 2
  • 55.
    Example D. a. If3(x – 2) = 0, then (x – 2) = 0, so x must be 2. Applications of Factoring To solve polynomial equation, 1. set one side of the equation to be 0, move all the terms to the other side. b. If (x + 1)(x – 2) = 0, then either (x + 1) = 0 or (x – 2) = 0, x = –1 or x = 2
  • 56.
    Example D. a. If3(x – 2) = 0, then (x – 2) = 0, so x must be 2. Applications of Factoring To solve polynomial equation, 1. set one side of the equation to be 0, move all the terms to the other side. 2. factor the polynomial, b. If (x + 1)(x – 2) = 0, then either (x + 1) = 0 or (x – 2) = 0, x = –1 or x = 2
  • 57.
    Example D. a. If3(x – 2) = 0, then (x – 2) = 0, so x must be 2. Applications of Factoring To solve polynomial equation, 1. set one side of the equation to be 0, move all the terms to the other side. 2. factor the polynomial, 3. get the answers. b. If (x + 1)(x – 2) = 0, then either (x + 1) = 0 or (x – 2) = 0, x = –1 or x = 2
  • 58.
    Example D. a. If3(x – 2) = 0, then (x – 2) = 0, so x must be 2. Applications of Factoring To solve polynomial equation, 1. set one side of the equation to be 0, move all the terms to the other side. 2. factor the polynomial, 3. get the answers. b. If (x + 1)(x – 2) = 0, then either (x + 1) = 0 or (x – 2) = 0, x = –1 or x = 2 Example E. Solve for x a. x2 – 2x – 3 = 0
  • 59.
    Example D. a. If3(x – 2) = 0, then (x – 2) = 0, so x must be 2. Applications of Factoring To solve polynomial equation, 1. set one side of the equation to be 0, move all the terms to the other side. 2. factor the polynomial, 3. get the answers. b. If (x + 1)(x – 2) = 0, then either (x + 1) = 0 or (x – 2) = 0, x = –1 or x = 2 Example E. Solve for x a. x2 – 2x – 3 = 0 Factor (x – 3)(x + 1) = 0
  • 60.
    Example D. a. If3(x – 2) = 0, then (x – 2) = 0, so x must be 2. Applications of Factoring To solve polynomial equation, 1. set one side of the equation to be 0, move all the terms to the other side. 2. factor the polynomial, 3. get the answers. b. If (x + 1)(x – 2) = 0, then either (x + 1) = 0 or (x – 2) = 0, x = –1 or x = 2 Example E. Solve for x a. x2 – 2x – 3 = 0 Factor (x – 3)(x + 1) = 0 There are two linear x–factors. We may extract one answer from each.
  • 61.
    Example D. a. If3(x – 2) = 0, then (x – 2) = 0, so x must be 2. Applications of Factoring To solve polynomial equation, 1. set one side of the equation to be 0, move all the terms to the other side. 2. factor the polynomial, 3. get the answers. b. If (x + 1)(x – 2) = 0, then either (x + 1) = 0 or (x – 2) = 0, x = –1 or x = 2 Example E. Solve for x a. x2 – 2x – 3 = 0 Factor (x – 3)(x + 1) = 0 Hence x – 3 = 0 or x + 1 = 0 There are two linear x–factors. We may extract one answer from each.
  • 62.
    Example D. a. If3(x – 2) = 0, then (x – 2) = 0, so x must be 2. Applications of Factoring To solve polynomial equation, 1. set one side of the equation to be 0, move all the terms to the other side. 2. factor the polynomial, 3. get the answers. b. If (x + 1)(x – 2) = 0, then either (x + 1) = 0 or (x – 2) = 0, x = –1 or x = 2 Example E. Solve for x a. x2 – 2x – 3 = 0 Factor (x – 3)(x + 1) = 0 Hence x – 3 = 0 or x + 1 = 0 x = 3 There are two linear x–factors. We may extract one answer from each.
  • 63.
    Example D. a. If3(x – 2) = 0, then (x – 2) = 0, so x must be 2. Applications of Factoring To solve polynomial equation, 1. set one side of the equation to be 0, move all the terms to the other side. 2. factor the polynomial, 3. get the answers. b. If (x + 1)(x – 2) = 0, then either (x + 1) = 0 or (x – 2) = 0, x = –1 or x = 2 Example E. Solve for x a. x2 – 2x – 3 = 0 Factor (x – 3)(x + 1) = 0 Hence x – 3 = 0 or x + 1 = 0 x = 3 or x = -1 There are two linear x–factors. We may extract one answer from each.
  • 64.
    b. 2x(x +1) = 4x + 3(1 – x) Applications of Factoring
  • 65.
    b. 2x(x +1) = 4x + 3(1 – x) Expand 2x2 + 2x = 4x + 3 – 3x Applications of Factoring
  • 66.
    b. 2x(x +1) = 4x + 3(1 – x) Expand 2x2 + 2x = 4x + 3 – 3x 2x2 + 2x = x + 3 Applications of Factoring
  • 67.
    b. 2x(x +1) = 4x + 3(1 – x) Expand 2x2 + 2x = 4x + 3 – 3x 2x2 + 2x = x + 3 Set one side 0 2x2 + 2x – x – 3 = 0 Applications of Factoring
  • 68.
    b. 2x(x +1) = 4x + 3(1 – x) Expand 2x2 + 2x = 4x + 3 – 3x 2x2 + 2x = x + 3 Set one side 0 2x2 + 2x – x – 3 = 0 2x2 + x – 3 = 0 Applications of Factoring
  • 69.
    b. 2x(x +1) = 4x + 3(1 – x) Expand 2x2 + 2x = 4x + 3 – 3x 2x2 + 2x = x + 3 Set one side 0 2x2 + 2x – x – 3 = 0 2x2 + x – 3 = 0 Factor (2x + 3)(x – 1) = 0 Applications of Factoring
  • 70.
    b. 2x(x +1) = 4x + 3(1 – x) Expand 2x2 + 2x = 4x + 3 – 3x 2x2 + 2x = x + 3 Set one side 0 2x2 + 2x – x – 3 = 0 2x2 + x – 3 = 0 Factor (2x + 3)(x – 1) = 0 Get the answers 2x + 3 = 0 Applications of Factoring or x – 1 = 0
  • 71.
    b. 2x(x +1) = 4x + 3(1 – x) Expand 2x2 + 2x = 4x + 3 – 3x 2x2 + 2x = x + 3 Set one side 0 2x2 + 2x – x – 3 = 0 2x2 + x – 3 = 0 Factor (2x + 3)(x – 1) = 0 Get the answers 2x + 3 = 0 2x = -3 Applications of Factoring or x – 1 = 0
  • 72.
    b. 2x(x +1) = 4x + 3(1 – x) Expand 2x2 + 2x = 4x + 3 – 3x 2x2 + 2x = x + 3 Set one side 0 2x2 + 2x – x – 3 = 0 2x2 + x – 3 = 0 Factor (2x + 3)(x – 1) = 0 Get the answers 2x + 3 = 0 2x = -3 x = -3/2 Applications of Factoring or x – 1 = 0
  • 73.
    b. 2x(x +1) = 4x + 3(1 – x) Expand 2x2 + 2x = 4x + 3 – 3x 2x2 + 2x = x + 3 Set one side 0 2x2 + 2x – x – 3 = 0 2x2 + x – 3 = 0 Factor (2x + 3)(x – 1) = 0 Get the answers 2x + 3 = 0 2x = -3 x = -3/2 Applications of Factoring or x – 1 = 0 x = 1
  • 74.
    b. 2x(x +1) = 4x + 3(1 – x) Expand 2x2 + 2x = 4x + 3 – 3x 2x2 + 2x = x + 3 Set one side 0 2x2 + 2x – x – 3 = 0 2x2 + x – 3 = 0 Factor (2x + 3)(x – 1) = 0 Get the answers 2x + 3 = 0 2x = -3 x = -3/2 Applications of Factoring or x – 1 = 0 x = 1 c. 8x(x2 – 1) = 10x
  • 75.
    b. 2x(x +1) = 4x + 3(1 – x) Expand 2x2 + 2x = 4x + 3 – 3x 2x2 + 2x = x + 3 Set one side 0 2x2 + 2x – x – 3 = 0 2x2 + x – 3 = 0 Factor (2x + 3)(x – 1) = 0 Get the answers 2x + 3 = 0 2x = -3 x = -3/2 Applications of Factoring or x – 1 = 0 x = 1 c. 8x(x2 – 1) = 10x Expand 8x3 – 8x = 10x
  • 76.
    b. 2x(x +1) = 4x + 3(1 – x) Expand 2x2 + 2x = 4x + 3 – 3x 2x2 + 2x = x + 3 Set one side 0 2x2 + 2x – x – 3 = 0 2x2 + x – 3 = 0 Factor (2x + 3)(x – 1) = 0 Get the answers 2x + 3 = 0 2x = -3 x = -3/2 Applications of Factoring or x – 1 = 0 x = 1 c. 8x(x2 – 1) = 10x Expand 8x3 – 8x = 10x Set one side 0 8x3 – 8x – 10x = 0
  • 77.
    b. 2x(x +1) = 4x + 3(1 – x) Expand 2x2 + 2x = 4x + 3 – 3x 2x2 + 2x = x + 3 Set one side 0 2x2 + 2x – x – 3 = 0 2x2 + x – 3 = 0 Factor (2x + 3)(x – 1) = 0 Get the answers 2x + 3 = 0 2x = -3 x = -3/2 Applications of Factoring or x – 1 = 0 x = 1 c. 8x(x2 – 1) = 10x Expand 8x3 – 8x = 10x Set one side 0 8x3 – 8x – 10x = 0 8x3 – 18x = 0
  • 78.
    b. 2x(x +1) = 4x + 3(1 – x) Expand 2x2 + 2x = 4x + 3 – 3x 2x2 + 2x = x + 3 Set one side 0 2x2 + 2x – x – 3 = 0 2x2 + x – 3 = 0 Factor (2x + 3)(x – 1) = 0 Get the answers 2x + 3 = 0 2x = -3 x = -3/2 Applications of Factoring or x – 1 = 0 x = 1 c. 8x(x2 – 1) = 10x Expand 8x3 – 8x = 10x Set one side 0 8x3 – 8x – 10x = 0 8x3 – 18x = 0 Factor 2x(2x + 3)(2x – 3) = 0
  • 79.
    b. 2x(x +1) = 4x + 3(1 – x) Expand 2x2 + 2x = 4x + 3 – 3x 2x2 + 2x = x + 3 Set one side 0 2x2 + 2x – x – 3 = 0 2x2 + x – 3 = 0 Factor (2x + 3)(x – 1) = 0 Get the answers 2x + 3 = 0 2x = -3 x = -3/2 Applications of Factoring or x – 1 = 0 x = 1 c. 8x(x2 – 1) = 10x Expand 8x3 – 8x = 10x Set one side 0 8x3 – 8x – 10x = 0 8x3 – 18x = 0 Factor 2x(2x + 3)(2x – 3) = 0 There are three linear x–factors. We may extract one answer from each.
  • 80.
    b. 2x(x +1) = 4x + 3(1 – x) Expand 2x2 + 2x = 4x + 3 – 3x 2x2 + 2x = x + 3 Set one side 0 2x2 + 2x – x – 3 = 0 2x2 + x – 3 = 0 Factor (2x + 3)(x – 1) = 0 Get the answers 2x + 3 = 0 2x = -3 x = -3/2 Applications of Factoring or x – 1 = 0 x = 1 c. 8x(x2 – 1) = 10x Expand 8x3 – 8x = 10x Set one side 0 8x3 – 8x – 10x = 0 8x3 – 18x = 0 Factor 2x(2x + 3)(2x – 3) = 0 x = 0 There are three linear x–factors. We may extract one answer from each.
  • 81.
    b. 2x(x +1) = 4x + 3(1 – x) Expand 2x2 + 2x = 4x + 3 – 3x 2x2 + 2x = x + 3 Set one side 0 2x2 + 2x – x – 3 = 0 2x2 + x – 3 = 0 Factor (2x + 3)(x – 1) = 0 Get the answers 2x + 3 = 0 2x = -3 x = -3/2 Applications of Factoring or x – 1 = 0 x = 1 c. 8x(x2 – 1) = 10x Expand 8x3 – 8x = 10x Set one side 0 8x3 – 8x – 10x = 0 8x3 – 18x = 0 Factor 2x(2x + 3)(2x – 3) = 0 x = 0 or 2x + 3 = 0 There are three linear x–factors. We may extract one answer from each.
  • 82.
    b. 2x(x +1) = 4x + 3(1 – x) Expand 2x2 + 2x = 4x + 3 – 3x 2x2 + 2x = x + 3 Set one side 0 2x2 + 2x – x – 3 = 0 2x2 + x – 3 = 0 Factor (2x + 3)(x – 1) = 0 Get the answers 2x + 3 = 0 2x = -3 x = -3/2 Applications of Factoring or x – 1 = 0 x = 1 c. 8x(x2 – 1) = 10x Expand 8x3 – 8x = 10x Set one side 0 8x3 – 8x – 10x = 0 8x3 – 18x = 0 Factor 2x(2x + 3)(2x – 3) = 0 x = 0 or 2x + 3 = 0 or 2x – 3 = 0 There are three linear x–factors. We may extract one answer from each.
  • 83.
    b. 2x(x +1) = 4x + 3(1 – x) Expand 2x2 + 2x = 4x + 3 – 3x 2x2 + 2x = x + 3 Set one side 0 2x2 + 2x – x – 3 = 0 2x2 + x – 3 = 0 Factor (2x + 3)(x – 1) = 0 Get the answers 2x + 3 = 0 2x = -3 x = -3/2 Applications of Factoring or x – 1 = 0 x = 1 c. 8x(x2 – 1) = 10x Expand 8x3 – 8x = 10x Set one side 0 8x3 – 8x – 10x = 0 8x3 – 18x = 0 Factor 2x(2x + 3)(2x – 3) = 0 x = 0 or 2x + 3 = 0 or 2x – 3 = 0 2x = -3 There are three linear x–factors. We may extract one answer from each.
  • 84.
    b. 2x(x +1) = 4x + 3(1 – x) Expand 2x2 + 2x = 4x + 3 – 3x 2x2 + 2x = x + 3 Set one side 0 2x2 + 2x – x – 3 = 0 2x2 + x – 3 = 0 Factor (2x + 3)(x – 1) = 0 Get the answers 2x + 3 = 0 2x = -3 x = -3/2 Applications of Factoring or x – 1 = 0 x = 1 c. 8x(x2 – 1) = 10x Expand 8x3 – 8x = 10x Set one side 0 8x3 – 8x – 10x = 0 8x3 – 18x = 0 Factor 2x(2x + 3)(2x – 3) = 0 x = 0 or 2x + 3 = 0 or 2x – 3 = 0 2x = -3 x = -3/2 There are three linear x–factors. We may extract one answer from each.
  • 85.
    b. 2x(x +1) = 4x + 3(1 – x) Expand 2x2 + 2x = 4x + 3 – 3x 2x2 + 2x = x + 3 Set one side 0 2x2 + 2x – x – 3 = 0 2x2 + x – 3 = 0 Factor (2x + 3)(x – 1) = 0 Get the answers 2x + 3 = 0 2x = -3 x = -3/2 Applications of Factoring or x – 1 = 0 x = 1 c. 8x(x2 – 1) = 10x Expand 8x3 – 8x = 10x Set one side 0 8x3 – 8x – 10x = 0 8x3 – 18x = 0 Factor 2x(2x + 3)(2x – 3) = 0 x = 0 or 2x + 3 = 0 or 2x – 3 = 0 2x = -3 2x = 3 x = -3/2 There are three linear x–factors. We may extract one answer from each.
  • 86.
    b. 2x(x +1) = 4x + 3(1 – x) Expand 2x2 + 2x = 4x + 3 – 3x 2x2 + 2x = x + 3 Set one side 0 2x2 + 2x – x – 3 = 0 2x2 + x – 3 = 0 Factor (2x + 3)(x – 1) = 0 Get the answers 2x + 3 = 0 2x = -3 x = -3/2 Applications of Factoring or x – 1 = 0 x = 1 c. 8x(x2 – 1) = 10x Expand 8x3 – 8x = 10x Set one side 0 8x3 – 8x – 10x = 0 8x3 – 18x = 0 Factor 2x(2x + 3)(2x – 3) = 0 x = 0 or 2x + 3 = 0 or 2x – 3 = 0 2x = -3 2x = 3 x = -3/2 x = 3/2 There are three linear x–factors. We may extract one answer from each.
  • 87.
    Exercise A. Usethe factored form to evaluate the following expressions with the given input values. Applications of Factoring 1. x2 – 3x – 4, x = –2, 3, 5 2. x2 – 2x – 15, x = –1, 4, 7 3. x2 – 2x – 1, x = ½ ,–2, –½ 4. x3 – 2x2, x = –2, 2, 4 5. x3 – 4x2 – 5x, x = –4, 2, 6 6. 2x3 – 3x2 + x, x = –3, 3, 5 B. Determine if the output is positive or negative using the factored form. 7. x2 – 3x – 4, x = –2½, –2/3, 2½, 5¼ 8. –x2 + 2x + 8, x = –2½, –2/3, 2½, 5¼ 9. x3 – 2x2 – 8x, x = –4½, –3/4, ¼, 6¼, 11. 4x2 – x3, x = –1.22, 0.87, 3.22, 4.01 12. 18x – 2x3, x = –4.90, –2.19, 1.53, 3.01 10. 2x3 – 3x2 – 2x, x = –2½, –3/4, ¼, 3¼,
  • 88.
    C. Solve thefollowing equations. Check the answers. Applications of Factoring 18. x2 – 3x = 10 20. x(x – 2) = 24 21. 2x2 = 3(x + 1) – 1 28. x3 – 2x2 = 0 22. x2 = 4 25. 2x(x – 3) + 4 = 2x – 4 29. x3 – 2x2 – 8x = 0 31. 4x2 = x3 30. 2x2(x – 3) = –4x 26. x(x – 3) + x + 6 = 2x2 + 3x 13. x2 – 3x – 4 = 0 14. x2 – 2x – 15 = 0 15. x2 + 7x + 12 = 0 16. –x2 – 2x + 8 = 0 17. 9 – x2 = 0 18. 2x2 – x – 1 = 0 27. x(x + 4) + 9 = 2(2 – x) 23. 8x2 = 2 24. 27x2 – 12 = 0 32. 4x = x3 33. 4x2 = x4 34. 7x2 = –4x3 – 3x 35. 5 = (x + 2)(2x + 1) 36. (x – 1)2 = (x + 1)2 – 4 37. (x + 1)2 = x2 + (x – 1)2 38. (x + 2)2 – (x + 1)2= x2 39. (x + 3)2 – (x + 2)2 = (x + 1)2