Question

which of the following expressions are equivalent to m/n^7?
A. -mn^7
B. mn^-7
C. -m/n^7
D. -m/n^-7

Answer 1

I think you mean $\frac{m}{n^7}$
remember
$\frac{1}{x^m}=x^{-m}$
so
$\frac{m}{n^7}=(m)(\frac{1}{n^7})=(m)(n^{-7})=mn^{-7}$
answer is B