Applicare la formula: $\frac{a^n}{a}$$=a^{\left(n-1\right)}$, dove $a^n/a=\frac{21x^3y^6}{7x^2y}$, $a^n=y^6$, $a=y$ e $n=6$

Applicare la formula: $\frac{a^m}{a^n}$$=a^{\left(m-n\right)}$, dove $a^n=x^2$, $a^m=x^3$, $a=x$, $a^m/a^n=\frac{21x^3y^{5}}{7x^2}$, $m=3$ e $n=2$

Applicare la formula: $\frac{ab}{c}$$=\frac{a}{c}b$, dove $ab=21xy^{5}$, $a=21$, $b=xy^{5}$, $c=7$ e $ab/c=\frac{21xy^{5}}{7}$