Question

Evaluate (12.1)²–(3.9)² without Multiplying​

Answer 1

a^2-b^2= (a-b) (a+b)
=(12.1-3.9)(12.1+3.9)
=8.2*16
=131.2

Answer 2

(12.1)^2 - (3.9)^2
=(12.1+3.9)(12.1-3.9)
=131.2