若实数x,y满足x2-2xy+y2+x-y-6=0,则x-y的值是(  ) A.-2或3 B.2或-3 C.-1或6 D.1或-6

问题描述:

若实数x,y满足x2-2xy+y2+x-y-6=0,则x-y的值是(  )
A. -2或3
B. 2或-3
C. -1或6
D. 1或-6

设x-y=m,则原方程可化为:
m2+m-6=0,
解得m1=2,m2=-3,
所以,x-y的值2或-3.
故选B.