若x^2-xy-2y^2-x-7y-6=(x-2y+m)(x+y+n) 求:m,n若x^2-xy-2y^2-x-7y-6=(x-2_数学解答

若x^2-xy-2y^2-x-7y-6=(x-2y+m)(x+y+n) 求:m,n
若x^2-xy-2y^2-x-7y-6=(x-2y+m)(x+y+n)
求:m,n

人气：115 ℃　时间：2020-10-02 00:48:39

解答

x^2-xy-2y^2-x-7y-6
=(x-2y)(x+y)-(x+7y)-6
=[(x-2y)-3][(x+y)+2]
=(x-2y-3)(x+y+2)
m=-3,n=2