1 （2x-3y)^2(2x+3y)^2 2 (2x+y-1)(2x+y+y) 3 (2+xy)(xy-2)-(-2+xy)^2 _数学解答

1 （2x-3y)^2(2x+3y)^2 2 (2x+y-1)(2x+y+y) 3 (2+xy)(xy-2)-(-2+xy)^2 4 (a+3b)^2-(2a-3b)(3b+2a)
麻烦给详解

人气：418 ℃　时间：2020-04-02 02:08:51

解答

1.（2x-3y)^2(2x+3y)^2 =[（2x-3y)(2x+3y)]^2=(4x^2-9y^2)^2=16x^4-72x^2y^2+81y^42.(2x+y-1)(2x+y+y)题目是不是打错了应该是(2x+y-1)(2x+y+1)吧=（2x+y)^2-1=4x^2+4xy+y^2-13.(2+xy)(xy-2)-(-2+xy)^2=(x^2y^2-4)-(...