Applicare la formula: $x+a=b$$\to x=b-a$, dove $a=5x$, $b=0$, $x+a=b=5x+3y=0$, $x=3y$ e $x+a=5x+3y$

Applicare la formula: $mx=ny$$\to \frac{m}{mcd\left(m,n\right)}x=\frac{n}{mcd\left(m,n\right)}y$, dove $x=y$, $y=x$, $mx=ny=3y=-5x$, $mx=3y$, $ny=-5x$, $m=3$ e $n=-5$

Applicare la formula: $\frac{a}{b}$$=\frac{a}{b}$, dove $a=3$, $b=3$ e $a/b=\frac{3}{3}$