已知A=6x²-4x-2,B=-2x²+5,C=2x-3,求(A+B)-[2A-(C-3B)]
问题描述:
已知A=6x²-4x-2,B=-2x²+5,C=2x-3,求(A+B)-[2A-(C-3B)]
答
(A+B)-[2A-(C-3B)]
=(6x²-4x-2-2x²+5)-(12x^2-8x-4-2x+3-6x^2+15)
=4X^2-4x+3-(6x^2-10x+14)
=-2x^2+6x-11