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:

The answer is

(i) 92 x 108 = 9936

(ii) 279 x 321 =89559

Step-by-step explanation:

(i) 92 x 108

92*108 can also be written as 108*92

108= 100 + 8

92= 100 - 8

 108*92

=(100+8)*(100-8)

=(a+b)*(a-b)

=a²-b²

=100²-8²

=10000-64

=9936

(ii) 279 x 321

=321*279

=(300+21)*(300-21)

=300²-21²

=90000-441

=89559