先化简,再求值 (1)[(x-y)的平方+(x+y)(x-y)]÷2x 其中X=2010,y=2009 (2)y(x+y)+(x+y)(x-y)-x的平方,先化简,再求值(1)[(x-y)的平方+(x+y)(x-y)]÷2x 其中X=2010,y=2009(2)y(x+y)+(x+y)(x-y)-x的平方,其中x=-2,y=二分
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先化简,再求值 (1)[(x-y)的平方+(x+y)(x-y)]÷2x 其中X=2010,y=2009 (2)y(x+y)+(x+y)(x-y)-x的平方,先化简,再求值(1)[(x-y)的平方+(x+y)(x-y)]÷2x 其中X=2010,y=2009(2)y(x+y)+(x+y)(x-y)-x的平方,其中x=-2,y=二分
先化简,再求值 (1)[(x-y)的平方+(x+y)(x-y)]÷2x 其中X=2010,y=2009 (2)y(x+y)+(x+y)(x-y)-x的平方,
先化简,再求值
(1)[(x-y)的平方+(x+y)(x-y)]÷2x 其中X=2010,y=2009
(2)y(x+y)+(x+y)(x-y)-x的平方,其中x=-2,y=二分之一
(3)x的平方-(x-1)-x(x的平方+x-1),其中X=二分之一
先化简,再求值 (1)[(x-y)的平方+(x+y)(x-y)]÷2x 其中X=2010,y=2009 (2)y(x+y)+(x+y)(x-y)-x的平方,先化简,再求值(1)[(x-y)的平方+(x+y)(x-y)]÷2x 其中X=2010,y=2009(2)y(x+y)+(x+y)(x-y)-x的平方,其中x=-2,y=二分
我用x2表示的x的平方
1,(x-y)2=x2-2xy+y2,(x+y)(x-y)=x2-y2,所以原式=(2x2-2xy)/2x=x-y=1
2,=xy+y2+x2-y2-x2=xy=-1
3,=x2-x+1-x3-x2+x=1-x3=7/8
1、原式=[x^2-2xy+y^2+x^2-y^2]/2x =1/2x-y+1/2x=x-y=2010-2009 =1 2、原式=yx+y^2+x^2-y^2-x^2=yx=1/2*-2=-1 原式=x^2-(x-1)-x^3-x^2+x=-x+1-x^3+x=1-x^3=1-1/8=7/8 ( 选我的吧!)(*^__^*) 嘻嘻……
(1) 1
(2) 5
(3) 7/8
1 [(x-y)²+(x+y)(x-y)]÷2x=(x²-2xy-y²+x²-y²)÷2x=(2x²-2xy)÷2x=x-y
2 y(x+y)+(x+y)(x-y)-x²=xy+y²+x²-y²-x²=xy
3 x²-(x-1)-x(x²+x-1)=x²-x+1-x³-x²+x=1-x³
(1)x-y=1
(2)xy=-1
(3)1-x3 =7/8
1 [(x-y)²+(x+y)(x-y)]÷2x=(x²-2xy-y²+x²-y²)÷2x=(2x²-2xy)÷2x=x-y
2 y(x+y)+(x+y)(x-y)-x²=xy+y²+x²-y²-x²=xy
3 x²-(x-1)-x(x²+x-1)=x²-x+1-x³-x²+x=1-x³