Applicare la formula: $\frac{a^m}{a^n}$$=a^{\left(m-n\right)}$, dove $a^n=a^{-6}$, $a^m=a^{-2}$, $a^m/a^n=\frac{-4a^{-2}b^4}{8a^{-6}b^{-3}}$, $m=-2$ e $n=-6$

Applicare la formula: $\frac{a^m}{a^n}$$=a^{\left(m-n\right)}$, dove $a^n=b^{-3}$, $a^m=b^4$, $a=b$, $a^m/a^n=\frac{-4a^{4}b^4}{8b^{-3}}$, $m=4$ e $n=-3$

Applicare la formula: $\frac{ab}{c}$$=\frac{a}{c}b$, dove $ab=-4a^{4}b^{7}$, $a=-4$, $b=a^{4}b^{7}$, $c=8$ e $ab/c=\frac{-4a^{4}b^{7}}{8}$