Answer
$\dfrac{1}{x^{10}}$
Work Step by Step
RECALL:
(i) $\dfrac{a^m}{a^n} = a^{m-n}. a \ne0$
(ii) $a^{-m} = \dfrac{1}{a^m}, a \ne0$
Use rule (i) above to obtain:
$=x^{-7-3}
\\=x^{-10}$
Use rule (ii) above to obtain:
$=\dfrac{1}{x^{10}}$
