Unit Test: We Distribute, Yet Things Multiply | Mathematics Class 8- New NCERT (Ganita Prakash) PDF Download

Time: 1 hour

M.M. 25

Attempt all questions.

• Question numbers 1 to 5 carry 1 mark each.
• Question numbers 6 to 8 carry 2 marks each.
• Question numbers 9 to 11 carry 3 marks each.
• Question number 12 carry 5 marks 

Q1: Which of the following is the distributive property of multiplication over addition?   (1 Mark)
a) (a + b)c = ab + c
b) a(b + c) = ab + ac
c) (a + b)c = a + bc
d) ab + c = (a + c)b

Q2: When both numbers in a product ab are increased by 1, the increase in the product is:   (1 Mark)
a) a + b
b) a + b + 1
c) ab + 1
d) a² + b²

Q3: Which identity represents the square of a sum?   (1 Mark)
a) (a – b)² = a² – 2ab + b²
b) (a + b)² = a² + 2ab + b²
c) (a + b)² = a² – 2ab + b²
d) (a – b)² = a² + 2ab + b²

Q4: If a = –5 and b = 8, then (a + 1)(b + 1) equals:   (1 Mark)
a) –36
b) –40
c) 36
d) –44

Q5: Use distributivity to calculate: 98 × 102   (1 Mark)
a) 10,004
b) 9,996
c) 9,980
d) 10,020

Q6: Evaluate algebraic expression ax² + by² – cz for x = 1, y = -1, z = 2, a = -2, b = 1, c = -2:   (2 Marks)

Q7: Solve (56 + a)(56 − a).  (2 Marks)

Q8: Solve 110 × 98   (2 Marks)

Q9: Simplify the algebraic expression: 2x²(x + 2) – 3x (x² – 3) – 5x(x + 5)  (3 Marks)

Q10: Factorise the expression 10x² + 5x + 2xy + y.  (3 Marks)

​You can access the solutions to this Unit Test here.