1.[1/2x-y)^2+(1/2x+y)^2](1/2x^2-2y^2) 2.(2x^3-5x-4)(3x^2-7x+8) 简便_数学解答

1.[1/2x-y)^2+(1/2x+y)^2](1/2x^2-2y^2) 2.(2x^3-5x-4)(3x^2-7x+8) 简便运算

人气：458 ℃　时间：2019-08-20 02:43:42

解答

原式=(1/4x²-xy+y²+1/4x²+xy+y²)(1/2x²-2y²)=(1/2x²+2y²)(1/2x²-2y²)=1/4x^4-4y^4原式=6x^5-14x^4+16x³-15x³+35x²-40x-12x²+28x-32=6x^5-14...