Answer
$3s^4$
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 variable to obtain:
$\require{cancel}=\dfrac{\cancel{15}3}{\cancel{5}}{s^{-4-(-8)}}
\\=3s^{-4+8}
\\=3s^4$
