作业帮已知A=x²-2xy+y,B=x²+2xy+y²-3,求2A-[B-(B-A)+2A+B] 急.
来源：学生作业帮助网 编辑：作业帮 时间：2024/05/04 01:40:02
![已知A=x²-2xy+y,B=x²+2xy+y²-3,求2A-[B-(B-A)+2A+B] 急.](/uploads/image/z/7191233-17-3.jpg?t=%E5%B7%B2%E7%9F%A5A%3Dx%26%23178%3B-2xy%2By%2CB%3Dx%26%23178%3B%2B2xy%2By%26%23178%3B-3%2C%E6%B1%822A-%5BB-%28B-A%29%2B2A%2BB%5D+%E6%80%A5.)
已知A=x²-2xy+y,B=x²+2xy+y²-3,求2A-[B-(B-A)+2A+B] 急.
已知A=x²-2xy+y,B=x²+2xy+y²-3,求2A-[B-(B-A)+2A+B] 急.
已知A=x²-2xy+y,B=x²+2xy+y²-3,求2A-[B-(B-A)+2A+B] 急.
解
2A-[B-(B-A)+2A+B]
=2A-[B-B+A+2A+B]
=2A-(B+3A)
=-B-A
=-(x²+2xy+y²-3)-(x²-2xy+y)
=-x²-2xy-y²+3-x²+2xy-y
=(-x²-x²)+(2xy-2xy)-y²-y+3
=-2x²-y²-y+3