Đáp án:
$(x,y)∈\{(7;-2);(-3;-4);(3;2);(1;-8)\}$
Lời giải:
$xy + 3x - 2y -6 = 5$
$⇒x(y+3)-2(y+3)=5$
$⇒(y+3)(x-2)=5$
TH1: $\left \{ {{y+3=1} \atop {x-2=5}} \right.$ $\Rightarrow$$\left \{ {{y=-2} \atop {x=7}} \right.$
TH2: $\left \{ {{y+3=-1} \atop {x-2=-5}} \right.$ $\Rightarrow$$\left \{ {{y=-4} \atop {x=-3}} \right.$
TH3: $\left \{ {{y+3=5} \atop {x-2=1}} \right.$ $\Rightarrow$$\left \{ {{y=2} \atop {x=3}} \right.$
TH4: $\left \{ {{y+3=-5} \atop {x-2=-1}} \right.$ $\Rightarrow$$\left \{ {{y=-8} \atop {x=1}} \right.$
Vậy $(x,y)∈\{(7;-2);(-3;-4);(3;2);(1;-8)\}$.
