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Algebraic Expressions and Identities — Class 8 CBSE Mathematics MCQs with Solutions
Free Class 8 CBSE Mathematics Algebraic Expressions and Identities MCQs with step-by-step solutions. Practise online on Prepizo — no login needed.
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Sample questions with solutions
Q1 — easy
How many terms are in the expression 4x² + 3x − 7?
A. 1
B. 2
C. 3 ✓ Correct
D. 4
Solution: Three terms separated by + and −.
Q2 — easy
Multiply: 2x × 3x
A. 5x
B. 6x
C. 5x²
D. 6x² ✓ Correct
Solution: 2 × 3 = 6 and x × x = x².
Q3 — easy
Simplify: 9y − 4y
A. 5
B. 5y ✓ Correct
C. 13y
D. 36y
Solution: Like terms subtract: 5y.
Q4 — hard
Simplify: (x + y)² − (x − y)²
A. 2xy
B. 4xy ✓ Correct
C. 2x²
D. 4x²
Solution: The difference of the two identities is 4xy.
Q5 — hard
Using an identity, evaluate 97².
A. 9109
B. 9209
C. 9409 ✓ Correct
D. 9509
Solution: (100−3)² = 10000 − 600 + 9 = 9409.
Q6 — hard
Factorise: x² − 16
A. (x−4)(x−4)
B. (x+4)(x+4)
C. (x+4)(x−4) ✓ Correct
D. (x+16)(x−1)
Solution: Difference of squares: a² − b² = (a+b)(a−b).
Q7 — medium
Find (a − b)² when a = 9 and b = 4.
A. 13
B. 25 ✓ Correct
C. 65
D. 97
Solution: (9−4)² = 25.
Q8 — medium
Simplify: (3x)² × 2x
A. 6x³
B. 9x³
C. 18x³ ✓ Correct
D. 18x²
Solution: 9x² × 2x = 18x³.
Q9 — medium
Using an identity, evaluate 102 × 98.
A. 9994
B. 9996 ✓ Correct
C. 9998
D. 10004
Solution: (100+2)(100−2) = 10000 − 4 = 9996.