xy=（x-5）*（y+2）{1}x-5=y+2 {2}解方程{1}得xy=xy+2x-5y-10 xy-xy=2x-5y-102x-5y-10=02x-5y=10{3}解方程{2}得x-y=7x=7+y{4}将{4}带入{3}中得2（7+y）-5y=1014+2y-5y=1014-3y=10-3y=-4y=3/4将y=3/4带入{4}中得x=31/... xy=（x-5）*（y+2）{1}x-5=y+2 {2}解方程{1}得xy=xy+2x-5y-10 xy-xy=2x-5y-102x-5y-10=02x-5y=10{3}解方程{2}得x-y=7x=7+y{4}将{4}带入{3}中得2（7+y）-5y=1014+2y-5y=1014-3y=10-3y=-4y=3/4将y=3/4带入{4}中得x=31/...