Aplicamos a regra: $a+\frac{b}{c}$$=\frac{b+ac}{c}$, onde $a=2$, $b=-1$, $c=x^2$, $a+b/c=2+\frac{-1}{x^2}$ e $b/c=\frac{-1}{x^2}$

Aplicamos a regra: $\frac{\frac{a}{b}}{c}$$=\frac{a}{bc}$, onde $a=-1+2x^2$, $b=x^2$, $c=x+4$, $a/b/c=\frac{\frac{-1+2x^2}{x^2}}{x+4}$ e $a/b=\frac{-1+2x^2}{x^2}$