This ppt prepared by Student-Teacher from Thigarajar College of Preceptors-Madurai for Demo class.

3. Algebraic expressions
Algebraic expressions Constants and Variables
 Algebraic expressions are
formed by using variables
constants and operations of
 Addition
 Subtraction
 Multiplications
 Division
 A collection of letters are
called Variables (eg: x,y,z )
 A collection of real numbers
are called Constants
(eg: 3,5,2)

4. TYPES OF ALGEBRAIC EXPRESSIONS
Polynomial
Monomial
7x
Binomial
3x – 2y
Trinomial
p+q+r

5. Value of algebraic expressions
 If X = 3 and Y= 2 then 2X + 3Y + 5,find the value
sol,
= 2(3)+3(2)+5
= 6+6+5
= 12+5
= 17

6. IDENTITIES
Definition
Special Identities
 An Identities is an equality which is true for all values of
variables in the equality
 Identity 1: (a+b)² =a²+ 2ab + b²
 Identity 2: (a-b)² =a²- 2ab + b²
 Identity 3: a² - b² =(a+b)(a-b)

7. • (x+7)²= ?
• a = x
• b = 7
• = x² + 2(x)(7)+7 ²
• = x² + 14x+49
Identity 1
• (x-7)² =?
• a = x
• b = 7
• = x² - 2(x)(7)+7 ²
• = x²-14x+49
Identity 2
• x² - 6² =?
• a² = x² => a = x
• b² = 6² => b = 6
• = (x + 6)(x- 6)
Identity 3
Examples For Identities

8. EVALUATION
Add the expressions
1. L² - M²,2 L² - M²
Subtract the expressions
1. bc – ca, ca- ab
Write the following in expanded form
1. (2x-3y)²