作业帮化简并求值 xy-2{xy-[3x²y-(xy²+0.5xy)]+4x²y},其中x=1,y=-2
来源：学生作业帮助网 编辑：作业帮 时间：2024/04/30 01:03:52
![化简并求值 xy-2{xy-[3x²y-(xy²+0.5xy)]+4x²y},其中x=1,y=-2](/uploads/image/z/1611783-63-3.jpg?t=%E5%8C%96%E7%AE%80%E5%B9%B6%E6%B1%82%E5%80%BC+xy-2%7Bxy-%5B3x%26%23178%3By-%28xy%26%23178%3B%2B0.5xy%29%5D%2B4x%26%23178%3By%7D%2C%E5%85%B6%E4%B8%ADx%3D1%2Cy%3D-2)
化简并求值 xy-2{xy-[3x²y-(xy²+0.5xy)]+4x²y},其中x=1,y=-2
化简并求值 xy-2{xy-[3x²y-(xy²+0.5xy)]+4x²y},其中x=1,y=-2
化简并求值 xy-2{xy-[3x²y-(xy²+0.5xy)]+4x²y},其中x=1,y=-2
xy-2{xy-[3x²y-(xy²+0.5xy)]+4x²y}
=xy-2[xy-(3x²y-xy²-0.5xy)+4x²y]
=xy-2(xy-3x²y+xy²+0.5xy+4x²y)
=xy-2xy+6x²y-2xy²-xy-8x²y
=-2xy-2x²y-2xy²
=-2*1*(-2)-2*1*(-2)-2*1*4
=4+4-8
=0