Applicare la formula: $x\cdot x^n$$=x^{\left(n+1\right)}$, dove $x^nx=\left(\frac{1}{2}x^2-4y\right)^2\left(\frac{1}{2}x^2-4y\right)$, $x=\frac{1}{2}x^2-4y$, $x^n=\left(\frac{1}{2}x^2-4y\right)^2$ e $n=2$

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

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

Applicare la formula: $\frac{a}{b}c$$=\frac{ca}{b}$, dove $a=1$, $b=4$, $c=-12$, $a/b=\frac{1}{4}$ e $ca/b=-12\cdot \left(\frac{1}{4}\right)x^{4}y$