Answer
Answer: $\frac{25a}{9a - 18}$
Work Step by Step
$\frac{5a + 10}{18}$ $\div$ $\frac{a^{2}-4}{10a}$
$\frac{5a + 10}{18}$ $\div$ $\frac{a^{2}+4}{10a}$ = $\frac{5a + 10}{18}$ $\times$ $\frac{10a}{a^{2}-4}$ = $\frac{5(a+2)}{2(9)}$ $\times$ $\frac{2(5a)}{(a+2)(a-2)}$
= $\frac{5}{9}$ $\times$ $\frac{5a}{(a-2)}$ ...(Since $\frac{2}{2}$ = 1 and $\frac{(a+2)}{(a+2)}$ = 1)
= $\frac{25a}{9a - 18}$
