Question

What is an efficient way to compute 47^2–37^2 without using raw calculations?

Answer 1

(47+37)(47-37)

Explanation:

47^2-37^2 is a difference of two squares. a^2-b^2 = (a+b)(a-b) so this expression can be factored to (47+37)(47-37) = (84)(10) = 840