将多项式x2+2xy+y2-2x-2y+1分解因式,正确的是(  ) A.(x+y)2 B.(x+y-1)2 C.(x+y+1)2 D.(x-y-1)2

问题描述:

将多项式x2+2xy+y2-2x-2y+1分解因式,正确的是(  )
A. (x+y)2
B. (x+y-1)2
C. (x+y+1)2
D. (x-y-1)2

x2+2xy+y2-2x-2y+1,
=(x2+2xy+y2)-(2x+2y)+1,
=(x+y)2-2(x+y)+1,
=(x+y-1)2