Algebraic Expressions.
Name: A.Yodha
Gopaal.
Introduction.
Algebraic expression
– a group of numbers,
symbols, and variables
that express an
operation or a series
of operations.EXAMPLES: a-8
b-2
z+12
etc……
DEFINITIONS
Variable – A variable is a
letter or symbol that
represents a number. It is
an unknown quantity
EXAMPLES: 5+z=13
expression –
To find the value of an
algebraic expression we can
substitute numbers for
variables.
Examples: m+7,m-3 etc…
(‘m’ variable can be any
number)
m + 8 if m = 2 then 2 + 8 =
10
z – 6 if z = 10 then 10
Like and unlike terms.
Like terms:
like terms are terms that
have the same variables
and powers.
Example: 8xyz2 and 5xyz2 are
like terms because they have
Unlike terms:
Unlike terms are two or
more terms that are not like
terms, i.e. they do not have the
same variables or powers.
Example: 3abc and 3ghi are
unlike terms because they have
different variables
Difference between like
and unlike terms.
1.Like terms can be added
together to simplify an
expression.
2.When adding like terms,
add the numerical
coefficients and retain the
variable.
Words That Lead to
Addition.
 Sum
 More than
 Increased
 Plus
 Altogether
Words That Lead to
Subtraction.
 Decreased
 Less
 Difference
 Minus
 How many
more
Terms and coefficients.
Terms:
Terms are the elements
separated by the plus or
minus signs.
Example: 3x2+2y+7xy+5
This example has
four terms, 3x2, 2y, 7xy,
Coefficients:
A number used to multiply a
variable.
Example: 6z means 6 times z,
and "z" is a variable, so 6 is a
coefficient.
Monomials,binomials,trinomial
s and polynomials .
Monomial:
An expression with one term
is called a monomial.
Binomial:
An expression with two terms
is called a binomial.
Trinomial:
An expression with three
terms is called a trinomial
Polynomial:
A polynomial is an expression
consisting of variables and
coefficients more than three
terms.
Examples:
Identity.
1. An identity is an
equality, which is true
for all values of the
variables in the equality
2. An equation is not an
identity.
Standard identities.
1) (a+b) 2 = a2 + 2ab +
b 2
2) (a-b) 2 = a2-2ab + b2
3) (a+b) (a-b) = a2- b 2
4) (x+a)(x+b)=x 2
+(a+b)x+ab
We can also write Algebraic
Expressions for These Word
Phrases
Ten more than a number n+10
A number decrease by 5 w-5
6 less than a number z-6
A number increased by 8 n+8
The sum of a number & 9 n+9
4 more than a number y+4
A number decrease by 1
k-1
31 less than a number
x-31
A number b increased by
7 b=7
The sum of a number & 6
n=6
Algebraic expressions

Algebraic expressions

  • 1.
  • 2.
    Introduction. Algebraic expression – agroup of numbers, symbols, and variables that express an operation or a series of operations.EXAMPLES: a-8 b-2 z+12 etc……
  • 3.
    DEFINITIONS Variable – Avariable is a letter or symbol that represents a number. It is an unknown quantity EXAMPLES: 5+z=13
  • 4.
    expression – To findthe value of an algebraic expression we can substitute numbers for variables. Examples: m+7,m-3 etc… (‘m’ variable can be any number) m + 8 if m = 2 then 2 + 8 = 10 z – 6 if z = 10 then 10
  • 5.
    Like and unliketerms. Like terms: like terms are terms that have the same variables and powers. Example: 8xyz2 and 5xyz2 are like terms because they have
  • 6.
    Unlike terms: Unlike termsare two or more terms that are not like terms, i.e. they do not have the same variables or powers. Example: 3abc and 3ghi are unlike terms because they have different variables
  • 7.
    Difference between like andunlike terms. 1.Like terms can be added together to simplify an expression. 2.When adding like terms, add the numerical coefficients and retain the variable.
  • 8.
    Words That Leadto Addition.  Sum  More than  Increased  Plus  Altogether
  • 9.
    Words That Leadto Subtraction.  Decreased  Less  Difference  Minus  How many more
  • 10.
    Terms and coefficients. Terms: Termsare the elements separated by the plus or minus signs. Example: 3x2+2y+7xy+5 This example has four terms, 3x2, 2y, 7xy,
  • 11.
    Coefficients: A number usedto multiply a variable. Example: 6z means 6 times z, and "z" is a variable, so 6 is a coefficient.
  • 12.
    Monomials,binomials,trinomial s and polynomials. Monomial: An expression with one term is called a monomial. Binomial: An expression with two terms is called a binomial.
  • 13.
    Trinomial: An expression withthree terms is called a trinomial Polynomial: A polynomial is an expression consisting of variables and coefficients more than three terms.
  • 14.
  • 15.
    Identity. 1. An identityis an equality, which is true for all values of the variables in the equality 2. An equation is not an identity.
  • 16.
    Standard identities. 1) (a+b)2 = a2 + 2ab + b 2 2) (a-b) 2 = a2-2ab + b2 3) (a+b) (a-b) = a2- b 2 4) (x+a)(x+b)=x 2 +(a+b)x+ab
  • 17.
    We can alsowrite Algebraic Expressions for These Word Phrases Ten more than a number n+10 A number decrease by 5 w-5 6 less than a number z-6 A number increased by 8 n+8 The sum of a number & 9 n+9 4 more than a number y+4
  • 18.
    A number decreaseby 1 k-1 31 less than a number x-31 A number b increased by 7 b=7 The sum of a number & 6 n=6