[(x+2xy)^2-(x+y)(3x-y)-5y^2]÷2x,其中x=-2,y=1/2
先化简再求值(x-y)(x+y)-(x-2y) 的完全平方+x(3x-5y)-(x-y)(x-2y),其中x=1/2 y
先化简,再求值(x-y/x+y)^2÷(y-x/x^2+2xy+y^2)^2*1/x+y,其中x=-4,y=1
[x(x-y)-y(x-y)+(x+y)(x-y)]÷2x其中x=2012 y=2013
先化简再求值:xy^3÷(-xy)+(x+2y)(x-2y),其中x=根号2,y=1
x+y)(x-y)+(x-y)^2-(6x^2y-2xy^2)/2y,其中x=-2,y=1/3
(x+2y-3xy)-(-2x-y+xy),其中x+y=1/2,xy=-1/2
5xy平方-2x平方y+[3xy平方-(4xy-2x平方y-2x平方y)],其中x=-2,y=-1求值
化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1
(x+2y-3y)- (-2x-y+xy ) 其中x+y=0.5 xy等于-0.5
[-(x-y)^2/xy]^-4*(y^2-xy/x)^3*(x^4/y^10)÷(xy-y^2/x)^-5=-y(y-
先化简再求值(x-y/1-x+y/1)÷x平方+2xy+y平方/2y,其中x=根号3+2,y=根号3
已知xy=-2,x-y=3,求(x+y)(x-y)-y^2+(x-y)^2-(6x^2y-2xy^2)÷2y