(x+y)^2/y^2-xy÷[-y^2+xy/(x-y)^2,x=0,y=根号10

x根号x+x根号y/xy-y^2)-（x+根号xy+y/x根号x-y根号）y 已知正实数x y满足x-根号xy-2y=0求 x+3根号xy+2y/2x-2根号下xy-y 已知x>0,y>0,且x+6y=5根号xy,求(2x+根号xy-y)分之(x+根号xy+2y)的值 已知：x>0,y>0,x-2y=根号xy.求（x+（根号xy）+y）/（x-（根号xy）-y） {（x-y)/(根号x+根号y)}-(x+y-2倍根号xy)/(根号x-根号y)=? [-(x-y)^2/xy]^-4*(y^2-xy/x)^3*(x^4/y^10)÷(xy-y^2/x)^-5=-y(y- (x+y)/(根号下x+根号下y)+2xy/(x根号下y+y根号下x)=______. 若x>0,y>0,且x-根号下xy-2y=0,求【2x-根号下xy】÷【y+2根号下xy】的值 已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值? 若根号x+y-3+绝对值xy+x+y-2=0,求x/y+y/x 先化简再求值：xy^3÷(-xy)+(x+2y)(x-2y),其中x=根号2,y=1 已知y=根号(x-8)+根号(8-x)+18,求代数式[(x+y)/(根号x+根号y)]-2xy/(x根号y-y根号x)