错了吧
应该是3x²+5xy-2y²+11x-6y-4
或3x²+5xy-2y²-11x+6y-4
或3x²-5xy-2y²+11x+6y-4
3x²+5xy-2y²+11x-6y-4
=(3x-y)(x+2y)+11x-6y-4
=(3x-y)(x+2y)-(x+2y)+12x-4y-4
=(3x-y-1)(x+2y)+4(3x-y-1)
=(3x-y-1)(x+2y+4)
3x²+5xy-2y²-11x+6y-4
=(3x-y)(x+2y)-11x+6y-4
=(3x-y)(x+2y)+(x+2y)-12x+4y-4
=(3x-y+1)(x+2y)-4(3x+y-1)
=(3x+y-1)(x+2y-4)
3x²-5xy-2y²+11x+6y-4
=(3x+y)(x-2y)+11x+6y-4
=(3x+y)(x-2y)-(x-2y)+12x-4y-4
=(3x+y-1)(x-2y)+4(3x-y-1)
=(3x+y-1)(x-2y+4)