`\qquad {((x+5)(y-2)=(x+2)(y-1)),((x-4)(y+7)=(x-3)(y+4)):}`
`<=> {(xy-2x+5y-10=xy-x+2y-2),(xy+7x-4y-28=xy+4x-3y-12):}`
`<=> {(x-3y=-8),(3x-y=16):}`
`<=> {(3x-9y=-24),(3x-y=16):}`
`<=> {(x-3y=-8),(8y=40):}`
`<=> {(x-3.5=-8),(y=5):}`
`<=> {(x=7),(y=5):}`
Vậy hệ pt có nghiệm duy nhất `(x;y)=(7;5)`