CBSE Maths · Class 8
Chapter 9: Algebraic Expressions and Identities
Name: ________________________
Date: ______________
Marks: ____ / 10
Expansions using identities: (a±b)2, (a+b)(a−b), (x+a)(x+b).
Questions
- Expand (3x−2y)2.
- Evaluate 982 using identity.
- (x+2)(x−3).
- (x+3)(x+5).
- (2a−3b)2.
- (102)2.
- 103×97.
- (a+2b)3.
- (x−4)(x+4).
- (a+b+c)2 expansion.
Extra Practice (Optional)
- Expand (2p−3q)(2p+3q).
- Evaluate 103×97.
- (5x−1)2.
Answer Key (For Teachers)
- Answer: 9x2−12xy+4y2.
Working: 9x2−12xy+4y2. - Answer: 9604.
Working: (100−2)2. - Answer: x2−x−6.
Working: x2−x−6. - Answer: x2+8x+15
Working: (x+a)(x+b) identity. - Answer: 4a2−12ab+9b2
Working: (a−b)2 pattern. - Answer: 10404
Working: (100+2)2. - Answer: 9991
Working: (a+b)(a−b). - Answer: a3+6a2b+12ab2+8b3
Working: Cube identity.
- Answer: x2−16
Working: a2−b2. - Answer: a2+b2+c2+2(ab+bc+ca)
Working: Formula.
Gyaan Maths · CBSE Class 8 · Chapter 9