已知x=根号3+1,y=根号3-1,求x^2-2xy-y^2得值
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
已知x平方+y平方-2y+1=0,求(根号x+根号y+3)/((根号xy+y)(3根号x+根号y))
已知根号x(根号x-根号y)=根号xy+3y,求(3x-y)分之2x+3倍根号xy-y 的值
已知x=1/根号3-根号2,y=1/根号3-根号2,求代数式x^2+xy+y^2的值!求
已知x,y为正数,且根号x(根号x+根号y)=3根号y(根号x+5根号y),求:(2x+根号xy+3y)/(x+根号xy
已知X—根号3XY-4Y=0,求(2X+3根号XY-2Y)/(3X-根号XY+Y)的值
1.若根号x-2=2,根号y-3=4,求xy的值.2.已知y=根号x-1+5根号1-x=2,求X方y的值.3.求根号x=
已知xy为实数,且y=根号4-x²+根号x²-4-1除以x+2,求根号3x+4y的值
已知y=2根号(3x-1)+3根号(1-3x)+1/2,求根号(xy)÷1/2根号(2/y)的值
1.已知x=1/2(根号5+根号3),y=1/2(根号5-根号3),求x^2+xy+y^2的值
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y根号[(x-1)/y]=负根号[(x-1)y],求xy的取值范围,并化简根号[2xy-(x^2+1)y]