负x减y括起来的平方减小括号2y减x乘小括号x加2y

2025-03-28 06:31:34
推荐回答(1个)
回答1:

负x减y括起来的平方减小括号2y减x乘小括号x加2y

解:
-(x-y)²-(2y-x)(x+2y)
=-(x-y)²+(x-2y)(x+2y)
=-x²+2xy-y²+x²-4y²
=-5y²+2xy