Applicare la formula: $\frac{a^m}{a^n}$$=a^{\left(m-n\right)}$, dove $a^n=x^2$, $a^m=x^8$, $a=x$, $a^m/a^n=\frac{-9x^8y^{11}z}{3x^2y^7}$, $m=8$ e $n=2$

Applicare la formula: $\frac{a^m}{a^n}$$=a^{\left(m-n\right)}$, dove $a^n=y^7$, $a^m=y^{11}$, $a=y$, $a^m/a^n=\frac{-9x^{6}y^{11}z}{3y^7}$, $m=11$ e $n=7$

Applicare la formula: $\frac{ab}{c}$$=\frac{a}{c}b$, dove $ab=-9x^{6}y^{4}z$, $a=-9$, $b=x^{6}y^{4}z$, $c=3$ e $ab/c=\frac{-9x^{6}y^{4}z}{3}$