Applicare la formula: $\left(a+b\right)^4$$=a^4+4a^3b+6a^2b^2+4ab^3+b^4$, dove $a=\frac{1}{3}y$, $b=-9x$ e $a+b=\frac{1}{3}y-9x$

Applicare la formula: $\left(ab\right)^n$$=a^nb^n$

Applicare la formula: $\frac{a}{b}c$$=\frac{ca}{b}$, dove $a=1$, $b=27$, $c=-36$, $a/b=\frac{1}{27}$ e $ca/b=-36\cdot \left(\frac{1}{27}\right)y^3x$

Applicare la formula: $\frac{a}{b}c$$=\frac{ca}{b}$, dove $a=1$, $b=9$, $c=6$, $a/b=\frac{1}{9}$ e $ca/b=6\cdot \left(\frac{1}{9}\right)y^2\left(-9x\right)^2$