Question

Expresia din imagine
Plz

Answer 1

$E(x)=( \frac{1}{x-1} - \frac{1}{x+1} ): \frac{1}{x^2-1} \\\\ E(x)= \frac{x+1-(x-1)}{(x-1)(x+1)} * \frac{(x-1)(x+1)}{1} \\\\ E(x)= \frac{x+1-x+1}{(x-1)(x+1)} * \frac{(x-1)(x+1)}{1} \\\\ E(x)= \frac{2}{1} \\\\ E(x)=2$