x^2-2xy+y^2+3x-3y+2
=(x-y)^2+3(x-y)+2
=(x-y+2)(x-y+1)
x^2+(a+1)x-(6a^2-13a+6)
=x^2+(a+1)x-(3a-2)(2a-3)
=(x+3a-2)(x-2a+3)
x＾2＋xy－2y＾2＋2x＋7y－3X
=(x+2y)(x-y)+2(x+2y)+3y-3x
=(x+2y)(x-y)+3(y-x)
=(x+2y-3)(x-y)