计算:[(x-y)^2-(x+y)^2]/(-4xy)=
(x^2+xy/x-y)/(xy/x-y)计算
x-y/xy-y^2计算
计算:4xy-(x+y)^2/xy(x+y)(x-y)÷x^2+xy-2y^2/x^2y+2xy^2
计算:(x+y/x-y)÷(xy+x^2)
计算 (-4/3xy)(-3x^2y)^2=( )
计算(xy-y^2)÷x-y/xy
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)
计算:(x-2y)(1+x+2y+4y^2+2xy+x^2)
计算4xy+(x-2y)的平方+(x+3y)(3y-x)
计算x²y³-2x(4xy³)
计算[4/(x^2-y^2)+(x+y)/(xy^2-x^2y)]除[(x+2y)(x-y)/(x^2+2xy^2)
计算3xy[2xy-x(y-2)+x-1]