Question

Evaluate the following products without multiplying directly(using suitable

identity)

i) 102X98

ii) 103X107​

Answer 1

Step-by-step explanation:

see i)

102×98

=(100+2)(100-2)

=(100)²–(4)²

=10000–16

=9984

Formula :a²–b²=(a+b)×(a–b)

(ii)

103×107

=(100+3)×(100+7) = (100)² + 100 (3+7) + (3×7)

= 10000 + 1000 + 21 = 11021

FORMULA - (x)² + x (a+b) + (a×b)