Question

Evaluate 121×99
With full process

Answer 1

Answer:

11979

Step-by-step explanation:

121*99

=(100+21)*(100-1)

using identity (x+a)(x+b)=x^2+(a+b)x+ab

when, x=100, a=21, b=-1

=100^2+(21-1)100+21*(-1)

=10000+2000-21

=11979