实数X,Y 满足x的平方减2xy加y的平方加x减y减6等于0，则x减y的值是? 急需，要步骤

x²-2xy+y²+x-y-6=0

(x²-2xy+y²)+(x-y)-6=0

(x-y)²+(x-y)-6=0

将(x-y)看作一个整体

[(x-y)+3][(x-y)-2]=0

(x-y)+3=0 或 (x-y)-2=0

x-y=-3 或 x-y=2

原式为（x^2-2xy+y^2）+x-y-6=0
变为（x-y)^2+(x-y)-6=0
设x-y=t 原式变为t^2+t-6=0
最后可算出t1=-3 t2=2
所以x-y=-3或2

原式化简为=(x-y)^2+(x-y)-6=0
把x-y 看为整体
解：（x-y+3)(x-y-2)=0
x-y=-3或x-y=2

X^2-XY+Y^2-XY+(X-Y)=6
X(X-Y)+Y(Y-X)+(X-Y)=6
(X-Y)^2+(X-Y)-6=0
(X-Y-3)(X-Y-2)=0
X-Y=3 X-Y=-2