先化简,再求值.已知x=-2,y=125分之一,求x(3x-2y)+(2x+y)²+(2x-y)(x+y)-3(xy+10)的值
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![先化简,再求值.已知x=-2,y=125分之一,求x(3x-2y)+(2x+y)²+(2x-y)(x+y)-3(xy+10)的值](/uploads/image/z/585360-0-0.jpg?t=%E5%85%88%E5%8C%96%E7%AE%80%2C%E5%86%8D%E6%B1%82%E5%80%BC.%E5%B7%B2%E7%9F%A5x%3D-2%2Cy%3D125%E5%88%86%E4%B9%8B%E4%B8%80%2C%E6%B1%82x%283x-2y%29%2B%282x%2By%29%26%23178%3B%2B%282x-y%29%28x%2By%29-3%28xy%2B10%29%E7%9A%84%E5%80%BC)
先化简,再求值.已知x=-2,y=125分之一,求x(3x-2y)+(2x+y)²+(2x-y)(x+y)-3(xy+10)的值
先化简,再求值.已知x=-2,y=125分之一,求x(3x-2y)+(2x+y)²+(2x-y)(x+y)-3(xy+10)的值
先化简,再求值.已知x=-2,y=125分之一,求x(3x-2y)+(2x+y)²+(2x-y)(x+y)-3(xy+10)的值
x(3x-2y)+(2x+y)²+(2x-y)(x+y)-3(xy+10)
=3x^2-2xy+4x^2+4xy+y^2+2x^2+xy-y^2-3xy-30
=9x^2-30
x=-2,
=36-30
=6
原式=3x(2)-2xy+4x(2)+y(2)+4xy+2x(2)+2xy-xy-y(2)-3xy-30
=9x(2)-30
=36-30
=6