Question

If a - b = 3 and a2 + b2 = 29, find the value of ab.

Answer 1

ab = 10

Process:-
(a-b)^2 + 2ab = a^2 + b^2
(3)^2 + 2ab = 29
9 + 2ab = 29
2ab = 29 - 9
2ab = 20
ab = 20/2
ab = 10