$\left \{ {{(x^2-y^2)+(x-y)=5} \atop {x^2(x-y)-y^2(x-y)=6}} \right.$
⇔$\left \{ {{(x^2-y^2)+(x-y)=5} \atop {(x^2-y^2)(x-y)=6}} \right.$
Suy ra:
TH1: $\left \{ {{x^2-y^2=2} \atop {x-y=3}} \right.$
⇔$\left \{ {{x^2-(x-3)^2=2} \atop {y=x-3}} \right.$
⇔$\left \{ {{x=11/6} \atop {y=-7/6}} \right.$
TH1: $\left \{ {{x^2-y^2=3} \atop {x-y=2}} \right.$
⇔$\left \{ {{x^2-(x-2)^2=3} \atop {y=x-2}} \right.$
⇔$\left \{ {{x=7/4} \atop {y=-1/4}} \right.$
