Applicare la formula: $a+\frac{b}{c}$$=\frac{b+ac}{c}$, dove $a=-1$, $c=a$, $a+b/c=\frac{b}{a}-1$ e $b/c=\frac{b}{a}$

Applicare la formula: $a+\frac{b}{c}$$=\frac{b+ac}{c}$, dove $a=1$, $b=a$, $c=b$, $a+b/c=\frac{a}{b}+1$ e $b/c=\frac{a}{b}$

Applicare la formula: $1x$$=x$, dove $x=b$

Applicare la formula: $\frac{\frac{a}{b}}{\frac{c}{f}}$$=\frac{af}{bc}$, dove $a=a+b$, $a/b/c/f=\frac{\frac{a+b}{b}}{\frac{b-a}{a}}$, $c=b-a$, $a/b=\frac{a+b}{b}$, $f=a$ e $c/f=\frac{b-a}{a}$