(3x+2x-8)^2-(x-2x-8)^2
问题描述:
(3x+2x-8)^2-(x-2x-8)^2
答
(3x²+2x-8)^2-(x²-2x-8)^2=(3x²+2x-8+x²-2x-8)(3x²+2x-8-x²+2x+8)=(4x²-16)(2x²+4x)=8(x²-4)(x²+2x)=8x(x+2)²(x-2)
(3x+2x-8)^2-(x-2x-8)^2
(3x²+2x-8)^2-(x²-2x-8)^2=(3x²+2x-8+x²-2x-8)(3x²+2x-8-x²+2x+8)=(4x²-16)(2x²+4x)=8(x²-4)(x²+2x)=8x(x+2)²(x-2)