Question

How to solve (a+b)^-2

Answer 1

= (a+b)^-2
= 1/(a+b)^2
= 1/(a^2 + b^2 + 2ab)

Answer 2

$= \frac{1}{ {(a + b)}^{2} } \\ = \frac{1}{ {a}^{2} + {b}^{2} + 2ab }$