Give me MCQs on identities for ICSE grade 9.
Answer (1)
Here are some multiple-choice questions (MCQs) on identities for ICSE Grade 9 Mathematics:
Identify the correct algebraic identity: ( a + b ) 2
a) a 2 + 2 ab + b 2 b) a 2 − 2 ab + b 2 c) a 2 + 2 a + b 2 d) a 2 + b 2
Correct Answer: a)
Which of the following is an identity?
a) a 2 + ab − ab
b) a 2 + 2 ab + b 2
c) a 2 − 4 ab
d) a + b
Correct Answer: b)
What is the expanded form of ( a − b ) 3 ?
a) a 3 − 3 a 2 b + 3 a b 2 − b 3
b) a 3 + 3 a 2 b + 3 a b 2 + b 3
c) a 3 − b 3
d) a 3 + b 3
Correct Answer: a)
If a = 3 and b = 4 , what is the value of ( a + b ) 2 + ( a − b ) 2 ?
a) 49 b) 50 c) 52 d) 54
Solution: First, apply the identities: ( a + b ) 2 = a 2 + 2 ab + b 2 ( a − b ) 2 = a 2 − 2 ab + b 2 So, ( a + b ) 2 + ( a − b ) 2 = 2 a 2 + 2 b 2 = 2 ( 9 ) + 2 ( 16 ) = 50 .
Correct Answer: b)
Which expression represents the formula ( a − b ) ( a + b ) ?
a) a 2 − b 2 b) a 2 + ab + b 2 c) a 2 + b 2 d) ab + ba
Correct Answer: a)
These MCQs cover key concepts of algebraic identities frequently taught in Grade 9 ICSE Mathematics. Make sure to understand these identities and practice them, as they form the basis for solving complex algebraic equations and modeling real-world applications.
