CBSE Class 8 Mathematics Algebraic Expressions and Identities Assignment Set A

Very Short Answer type Questions

Question. If a = 3, b = 4 and x = 5. Find the value of (x + a) (x + b),
Answer : 72

Question. Simplify 4x² - 9y² / 2x + 3y
Answer : 2x – 3y

Question. Find (3pq + 4q)² – (3pq – 4q)².
Answer : 48pq²

Question. Find the value of (2/3 m - 3/2n)² + 2mn
Answer : 4/9m² + 9/4n²

Question. What should be added to a² + b² to get (a – b)².
Answer : –2ab

Question. Find the product of (t + s²) (t² – s).
Answer : t³ + t²s² – st – s³

Question. Find the product of (4m + 3) (4m + 1)
Answer : 16m² + 16m + 3

Question. Simplify 9x² + 16y² + 24xy / 3x + 4y
Answer : 3x + 4y

Question. Find the product of (xyz – 3) (xyz – 2).
Answer : x²y²z² – 5xyz + 6

Question. Simplify : (2x + 5)² – (2x – 5)².
Answer : 40x

Question. Simplify : (m² + 9) (m² – 9) + 81.
Answer : m⁴

Question. Multiply : (2.5m – 0.5n) (2.5m + 0.5n).
Answer : 6.25m² – 0.25n²

Question. Multiply : (a + 1) (a + 2)
Answer : a² + 3a + 2

Question. Simplify 6.25m² - 2.25n² / 2.5m - 1.5n
Answer : 2.5m + 1.5n

Question. Find the value of (4.9)².
Answer : 24.01

Algebraic Expressions and Identities

Q 1 Using identity (x - a) (x + a) = x² – a² find 6² – 5².

Q 2 Find the product of (7x – 4y) and (3x - 7y).

Q 3 Using suitable identity find (a + 3)(a + 2).

Q 4 Using identity (a + b)² = a² + 2ab + b² find the value of 103².

Q 5 Using identity (a – b)² = a² – 2ab + b² find the value of 98².

Q 6 Using identity find (2x +3)².

Q 7 Subtract 7x - 3x² from 4x + 8x².

Q 8 Using suitable identity find (7x - 3y)².

Q 9 Add 4x² + 2xy – 4 and 7x² – 3xy + 4.

Q 10 Find the product of 4x, 7x², -2x.

Q 11 Find the product of (x² – y²)(2x + y).

Q 12 Simplify: (xy + yz)² – (xy – yz)²

Q 13 Multiply: (a² + 2c²) (3a – 3c)

Q 14 Simplify: (x + y) (2x – 3y + z) – (2x – 3y)z