Applicare la formula: $x+a=b$$\to x=b-a$, dove $a=2b$, $b=0$, $x+a=b=5a+2b=0$, $x=5a$ e $x+a=5a+2b$

Applicare la formula: $mx=ny$$\to \frac{m}{mcd\left(m,n\right)}x=\frac{n}{mcd\left(m,n\right)}y$, dove $x=a$, $y=b$, $mx=ny=5a=-2b$, $mx=5a$, $ny=-2b$, $m=5$ e $n=-2$

Applicare la formula: $\frac{a}{b}$$=\frac{a}{b}$, dove $a=5$, $b=5$ e $a/b=\frac{5}{5}$