Question

If ab=8 and a^2+b^2=16, what is the value of (a+b)^2

Answer 1

Explanation:

well, do the multiplication of the square and compare the parts of the expression.

(a + b)² = (a + b)(a + b) = a² + ab + ab + b² =

= a² + 2ab + b² = a² + b² + 2ab

a² + b² = 16

ab = 8

so, we have

(a+b)² = 16 + 2×8 = 16 + 16 = 32