已知实数x满足x^2+2xy+y^2-(x+y)-6=0则x+y的值

已知实数x满足x^2+2xy+y^2-(x+y)-6=0则x+y的值
已知实数x满足x^2+2xy+y^2-(x+y)-6=0则x+y的值

已知实数x满足x^2+2xy+y^2-(x+y)-6=0则x+y的值
x^2+2xy+y^2-(x+y)-6=0
(x+y)^2-(x+y)-6=0
令x+y为a
即 a^2-a-6=0
(a-3)(a+2)=0
所以 a=3或a=-2
故x+y=3或-2