Answer
$\color{blue}{\dfrac{3}{5a^3b^5}}$
Work Step by Step
RECALL:
(1) $a^{-m} = \dfrac{1}{a^m}$
(2) $\dfrac{a^m}{a^n} = a^{m-n}$
(3) $\left(\dfrac{a}{b}\right)^m=\dfrac{a^m}{b^m}$
(4) $(ab)^m = a^mb^m$
Divide the coefficients together by canceling common factors, then use rule (2) above to simplify the variables to obtain:
$\require{cancel}=\dfrac{\cancel{15}3}{\cancel{25}5}a^{-5-(-2)}b^{-1-4}
\\=\dfrac{3}{5}a^{-5+2}b^{-5}
\\=\dfrac{3}{5}a^{-3}b^{-5}$
Use rule (1) above to obtain:
$=\dfrac{3}{5} \cdot \dfrac{1}{a^3} \cdot \dfrac{1}{b^5}
\\=\color{blue}{\dfrac{3}{5a^3b^5}}$