CBSE · Class 6-12

Class 9 · Ganita Manjari

Unit 4 · Class 9Ganita Manjari

Exploring Algebraic Identities

Key identities and their use in expansion & factorisation.

Lessons

4 concepts

1
Squared Binomials
Expand carefully — students often forget the middle term. Verify by multiplying out.
2
Difference of Squares
$a^2-b^2$ factorises easily. Very useful in simplifying algebraic fractions.
3
Cubed Binomials
$(a+b)^3 = a^3 + 3a^2b + 3ab^2 + b^3$ . Note the binomial coefficients 1, 3, 3, 1.
4
Sum & Difference of Cubes
$a^3\pm b^3$ factorises using two-factor form. Second factor is always $a^2 \mp ab + b^2$ .

Skills to practise

Skill · medium

Exploring Algebraic Identities — Practice