Giải thích các bước giải:
$\frac{ 3x-3}{x+2}$ . $\frac{x^2-4}{x^2-1}$
⇔ $\frac{3(x-1)}{x+2}$ . $\frac{x^2-4}{x^2-1}$
⇔ $\frac{3(x-1)}{x+2}$ . $\frac{x^2-2^2}{x^2-1}$
⇔ $\frac{3(x-1)}{x+2}$ . $\frac{(x+2)(x-2)}{x^2-1}$
⇔ $\frac{3(x-1)}{x+2}$ . $\frac{(x+2)(x-2)}{x^2-1^2}$
⇔ $\frac{3(x-1)}{x+2}$ . $\frac{(x+2)(x-2)}{(x+1)(x-1)}$
⇔ 3 (x - 1) . $\frac{x-2}{(x+1)(x-1)}$
⇔ 3 . $\frac{x-2}{x+1}$
⇔ $\frac{3(x-2)}{x+1}$
xin hay nhất! :)))
