Applicare la formula: $\frac{a}{b}$$=\frac{a}{b}\frac{conjugate\left(b\right)}{conjugate\left(b\right)}$, dove $a=1$, $b=1+\sqrt{2}$ e $a/b=\frac{1}{1+\sqrt{2}}$

Applicare la formula: $\frac{a}{b}\frac{c}{f}$$=\frac{ac}{bf}$, dove $a=1$, $b=1+\sqrt{2}$, $c=1-\sqrt{2}$, $a/b=\frac{1}{1+\sqrt{2}}$, $f=1-\sqrt{2}$, $c/f=\frac{1-\sqrt{2}}{1-\sqrt{2}}$ e $a/bc/f=\frac{1}{1+\sqrt{2}}\cdot \frac{1-\sqrt{2}}{1-\sqrt{2}}$

Applicare la formula: $a+b$$=a+b$, dove $a=1$, $b=-2$ e $a+b=1-2$