Answer
The answer is $\frac{1}{(a+b)}$
Work Step by Step
to solve for $(a+b)^{2}$$\times$$(a+b)^{-3}$ it becomes $\frac{(a+b)^{2}}{(a+b)^{3}}$. Since the base is same and the exponent is larger on the denominator, you subtract the exponent of the numerator from the denominator and so 3-2 equals which means you have only one (a+b) on the denominator and 1 on the numerator.
Therefore, the simplified answer is $\frac{1}{(a+b)}$