(3x+2y)(4x-5y)-12(x+y)(x-y)+7xy,其中x=2011,y=-1,
化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1
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
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
x²+xy/(x-4y)(x+y),其中x=4,y=-1
(3x+2y)(4x-5y)-11(x+y)(x-y)+5xy,其中x=2分之七,y=-2分之5
x+y)(x-y)+(x-y)^2-(6x^2y-2xy^2)/2y,其中x=-2,y=1/3
若x+y=-1,则x^4+5x^3y+x^2y+8x^2y^2+xy^2+5xy^3+y^4=( )
计算(x^8-x^7y+x^5y^3-x^4y^4+x^3y^5-x^y^7+y^8)(x^2+xy+y^2)
x^8-x^7y+x^6y^2-x^5y^3+x^4y^4-x^3y^5+x^2y^-xy^7+y^8
(x+2y-3xy)-(-2x-y+xy),其中x+y=1/2,xy=-1/2
[-(x-y)^2/xy]^-4*(y^2-xy/x)^3*(x^4/y^10)÷(xy-y^2/x)^-5=-y(y-