化简求值：x(x+2y)-(x+1)²+2x,其中x=1/25,y=-25

化简求值：x(x+2y)-(x+1)²+2x,其中x=1/25,y=-25

x(x+2y)-(x+1)²+2x
=x²+2xy-(x²+2x+1)+2x
=2xy-1
=2*(1/25)*(-25)-1
=-3
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x平方约掉2x约掉只剩2xy-1带入值，解得-3

原式=x^2+2xy-x^2-2x-1+2x=2xy-1
代入，得-3