Question

Use the identity (a + b)(a - b) = a2 - b2 to answer the questions.
(i) 92 x 108 (ii) 279 x 321

Answer 1

Answer:

92=(99-7)

108=(99+7)

now,

92×108=(99-7)×(99+7)

(a-b)×(a+b)=a^2-b^2

therefore, (99)2-(7)2=9801-49 = 9752.

Answer 2

Answer:

(i) 92*108

(100-8)(100+8)

(100)2-(8)2

10000-64

9963 answer

(i) 279*321

(300-21)(300+21)

(300)2-(21)2

90000-441

89559 answer