(2x-1)^2-(4x+3)(x-6)
问题描述：
(2x-1)^2-(4x+3)(x-6)
答
(2x-1)^2-(4x+3)(x-6)
=4x²-4x+1-(4x²-24x+3x-18)
=4x²-4x+1-4x²+21x+18
=17x+19