(x-5y)(-x-5y)-(-x+5y)^2,其中x=0.5,y=-1.计算

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(x-5y)(-x-5y)-(-x+5y)^2,其中x=0.5,y=-1.计算(x-5y)(-x-5y)-(-x+5y)^2,其中x=0.5,y=-1.计算(x-5y)(-x-5y)-(-x+5y)^

(x-5y)(-x-5y)-(-x+5y)^2,其中x=0.5,y=-1.计算
(x-5y)(-x-5y)-(-x+5y)^2,其中x=0.5,y=-1.计算

(x-5y)(-x-5y)-(-x+5y)^2,其中x=0.5,y=-1.计算
(x-5y)(-x-5y)-(-x+5y)^2
=(-5y+x)(-5y-x)-(x^2-10xy+25y^2
=25y^2-x^2-x^2+10xy-25y^2
=10xy-2x^2
=10*0.5*(-1)-2*0.5^2
=-5-0.5
=-5.5