(3x+1)(x-1)-(x+3)(5x-6)=-2x^2-11x+m,则m=?
问题描述:
(3x+1)(x-1)-(x+3)(5x-6)=-2x^2-11x+m,则m=?
答
(3x+1)(x-1)-(x+3)(5x-6)
=3x²-2x-1-(5x²+9x-18)
= -2x²-11x+17
因为(3x+1)(x-1)-(x+3)(5x-6)=-2x^2-11x+m
所以: -2x²-11x+17=-2x^2-11x+m
m=17