注:原题有误,应是以下两种情况之一:
x^2+y^2+2xy-4x-4y+3
=(x+y)^2-4(x+y)+3
=(x+y-3)(x+y-1)
或:
x^2+y^2+2xy+4x+4y+3
=(x+y)^2+4(x+y)+3
=(x+y+3)(x+y+1)
注:原题有误,应是以下两种情况之一:
x^2+y^2+2xy-4x-4y+3
=(x+y)^2-4(x+y)+3
=(x+y-3)(x+y-1)
或:
x^2+y^2+2xy+4x+4y+3
=(x+y)^2+4(x+y)+3
=(x+y+3)(x+y+1)