Question

Упростить выражение:left( {frac{2}{{{x^2} - 1}} + frac{1}{{x + 1}}} right)({x^2} - x) - x

Answer 1

$left( {frac{2}{{{x^2} - 1}} + frac{1}{{x + 1}}} right)({x^2} - x) - x=left( {frac{2}{{(x - 1)(x+1)}} + frac{1}{{x + 1}}} right)({x^2} - x) - x=\ =left( {frac{2}{{(x-1)(x+1)}} + frac{x-1}{{(x-1)(x + 1)}}} right)({x^2} - x) - x = frac{(x+1)cdot x(x-1)}{(x-1)(x+1)}-x= \ =x-x=0$