6x^2-xy-y^2+5x-5y-4,再有理数范围内因式分解

题目

6x^2-xy-y^2+5x-5y-4,再有理数范围内因式分解

答案

6x²-xy-y²+5x-5y-4
=(2x-y)(3x+y)+4(2x-y)-(3x+y)-4
=(2x-y)(3x+y+4)-(3x+y+4)
=(2x-y-1)(3x+y+4)