Q2 of 86 Page 56

Evaluate the following products without actual multiplication.

101 × 99

101 can be written as (100 + 1) and


99 can be written as (100 - 1)


⇒ 101 × 99 = (100 + 1) × (100 - 1)


using the identity (a + b) × (a – b) = a2 – b2


here a = 100 and b = 1


⇒ 101 × 99 = 1002 – 12


⇒ 101 × 99 = 10000 – 1


⇒ 101 × 99 = 9999


More from this chapter

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1

Use suitable identities to find the following products

 1

Use suitable identities to find the following products

(1 + x) (1 + x)

 2

Evaluate the following products without actual multiplication.

999 × 999

 2

Evaluate the following products without actual multiplication.