Applicare la formula: $x^a$$=\frac{1}{x^{\left|a\right|}}$

Applicare la formula: $a+\frac{b}{c}$$=\frac{b+ac}{c}$, dove $a=\frac{1}{x^{2}}$, $b=-1$, $c=y^{2}$, $a+b/c=\frac{1}{x^{2}}+\frac{-1}{y^{2}}$ e $b/c=\frac{-1}{y^{2}}$

Applicare la formula: $a+\frac{b}{c}$$=\frac{b+ac}{c}$, dove $a=-1$, $b=y^{2}$, $c=x^{2}$, $a+b/c=-1+\frac{y^{2}}{x^{2}}$ e $b/c=\frac{y^{2}}{x^{2}}$

Applicare la formula: $\frac{a}{b}\frac{c}{f}$$=\frac{ac}{bf}$, dove $a=1$, $b=x^{2}$, $c=1$, $a/b=\frac{1}{x^{2}}$, $f=y^{2}$, $c/f=\frac{1}{y^{2}}$ e $a/bc/f=\frac{1}{x^{2}}\frac{1}{y^{2}}$

Applicare la formula: $\frac{\frac{a}{b}}{\frac{c}{f}}$$=\frac{af}{bc}$, dove $a=\frac{y^{2}-x^{2}}{x^{2}}$, $b=y^{2}$, $a/b/c/f=\frac{\frac{\frac{y^{2}-x^{2}}{x^{2}}}{y^{2}}}{\frac{1}{x^{2}y^{2}}}$, $c=1$, $a/b=\frac{\frac{y^{2}-x^{2}}{x^{2}}}{y^{2}}$, $f=x^{2}y^{2}$ e $c/f=\frac{1}{x^{2}y^{2}}$