Applicare la formula: $ax+by$$=\left(\frac{a}{mcd\left(a,b\right)}x+\frac{b}{mcd\left(a,b\right)}y\right)mcd\left(a,b\right)$, dove $a=36$, $b=-32$, $ax+by=36x^8-32x^4+9$, $ax=36x^8$, $by=-32x^4$, $x=x^8$ e $y=x^4$

Applicare la formula: $x\left(a+b\right)$$=xa+xb$, dove $a=x^8$, $b=-\frac{8}{9}x^4$, $x=4$ e $a+b=x^8-\frac{8}{9}x^4$