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

Applicare la formula: $\frac{a}{b}\frac{c}{f}$$=\frac{ac}{bf}$, dove $a=1$, $b=3x$, $c=4y$, $a/b=\frac{1}{3x}$, $f=9x^2$, $c/f=\frac{4y}{9x^2}$ e $a/bc/f=\frac{1}{3x}\frac{4y}{9x^2}$

Applicare la formula: $ab$$=ab$, dove $ab=3\cdot 9xx^2$, $a=3$ e $b=9$

Applicare la formula: $x\cdot x^n$$=x^{\left(n+1\right)}$, dove $x^nx=27x\cdot x^2$, $x^n=x^2$ e $n=2$

Applicare la formula: $a+b$$=a+b$, dove $a=2$, $b=1$ e $a+b=2+1$