化简根号9x^3y^2(x+y)^3

化简求值:根号x^-2xy+y^2 + x^2 -6xy+9y^2/x-3y,其中x=根号3,y=根号5 化简:((根号x-根号y)^3+2x根号x+y根号y)/(x根号x+y根号y)+(3根号xy-3y)/(x-y) 已知x=2y,化简根号y/(根号x-根号y)-根号y/(根号x+根号y) 代数式求值.已知x=2,y=根号3,求 (根号x-根号y)/(根号x+根号y)+(根号x+根号y)/(根号x-根号y) 【(x-y)^3(x^1/2+y^1/2)^-3+3(x根号y-y根号x)】/(x根号x+y根号y)+(2xy根号xy- 计算：（2/3x根号下9x+6x根号下y/x）+（y根号下x/y-x的平方根号下1/x)= 已知实数x.y满足根号(x+y-8)+根号(8-x-y)=根号(3x-y-4)+根号(x-2y+7),求x,y 已知y=根号1-x+根号x-1+3,求根号x+根号y分之x+2根号xy+y+根号x-根号y分之一的值 求导数 y=(x*根号x根号x根号x)/3次根号x^2 化简求值:(1)已知x、y为实数,y=(根号(x^2-9)+根号(9-x^2)+1)/(x-3) x^2+y^2-4x-6y+13=0,求(2/3根号9x+y^2根号x/y^3)-x^2根号1/x-5x根号y/x)的值 已知实数x,y满足下x^2+根号2y=根号3,y^2+根号2x=根号3,求x/y+y/x