(x-2)(x+2)-(x-2)(x+2)-(x-1)(x+3)-(x+2)还有（2x+3y-2)(2x-3y+2)还有已知xy&_数学解答

(x-2)(x+2)-(x-2)(x+2)-(x-1)(x+3)-(x+2)还有（2x+3y-2)(2x-3y+2)
还有已知xy²=-2 求xy（2x³y^7-5x²y^5-y）
坐等
我搞错了(x-2)(x+2)-(x-1)(x+3)-(x+2)²

人气：427 ℃　时间：2020-04-10 07:29:39

解答

(x-2)(x+2)-(x-2)(x+2)-(x-1)(x+3)-(x+2)=-(x-1)(x+3)-(x+2)=-x²-2x+3-x-2=-x²-3x+1(2x+3y-2)(2x-3y+2) =[2x+(3y-2)][2x-(3y-2)]=4x²-(3y-2)²=4x²-9y²+12y-4xy（2x³y^7-5x²...