Answer
$\dfrac{1}{x^6}$
Work Step by Step
RECALL:
(i) $\dfrac{a^m}{a^n} = a^{m-n}, a \ne 0$
(ii) $a^{-m} = \dfrac{1}{a^m}, a\ne0$
(iii) $\dfrac{1}{a^{-m}}=a^m, a\ne0$
Use the rule (i) above to obtain:
$=x^{3-9}
\\=x^{-6}$
Use rule (ii) above to obtain:
$=\dfrac{1}{x^6}$
