分解因式x²-xy-6y²+2x-y+1
问题描述：
分解因式x²-xy-6y²+2x-y+1
答
x²-xy-6y²+2x-y+1
=(x-3y)(x+2y)+(x-3y)+(x+2y)+1
=(x-3y+1)(x+2y+1)