Răspuns:
[tex]E(x)=(\frac{2}{x-2}+\frac{x}{x+2}):\frac{x^{2}+4}{x^{2}-x-2}\\ \\=\frac{2(x+2)+x(x-2)}{(x+2)(x-2)}*\frac{x^{2}-x-2}{x^{2}+4}\\ \\=\frac{x^{2}+4}{(x+2)(x-2)}*\frac{x^{2}+x-2x-2}{x^{2}+4}\\ \\=\frac{x(x+1)-2(x+1)}{(x+2)(x-2)}\\\\=\frac{(x-2)(x+1)}{(x+2)(x-2)}\\ \\=\frac{x+1}{x+2}[/tex]