Bạn tham khảo nhé
$\left \{ {{\frac{2}{x+1} + \frac{3}{y} = -1} \atop {\frac{2}{x+1} + \frac{5}{y} = 1}} \right.$ (1)
* ĐK: x + 1 $\neq$ 0 <=> x $\neq$ -1
y $\neq$ 0
Đặt $\frac{1}{x+1}$ = u (u > 0)
$\frac{1}{ y }$ = v (v > 0)
(1) <=> $\left \{ {{2u+3v=-1} \atop {2u+5v=1}} \right.$
<=> u = -2, v = 1
Vì $\frac{1}{x+1}$ = u => $\frac{1}{x+1}$ = -2 => x = -$\frac{1}{2}$
$\frac{1}{ y }$ = v => $\frac{1}{ y }$ = 1 => y = 1
Vậy x = -$\frac{1}{2}$
y = 1.
