Answer
$-\dfrac{12}{x^7}$
Work Step by Step
RECALL:
(i) $a^m \cdot a^n = a^{m+n}$
(ii) $a^{-m} = \dfrac{1}{a^m}, a\ne0$
Multiply the numerical coefficients then use rule (i) above to obtain:
$=-12x^{4+(-11)}
\\=-12x^{-7}$
Use rule (ii) above to obtain:
$=-12 \cdot \dfrac{1}{x^7}
\\=-\dfrac{12}{x^7}$
