1/x^2+1/y^2-6/x-8/y+25=0
{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1
已知x.x+y.y+8x+6y+25=0,求代数式(x.x-4y.y)/(x.x+4xy+4y.y)-x/(x+2y)的
已知1/X^2 +1/Y^2 -6/X -8/Y +25=0求X+Y/XY的值
设x>1,y>0,若x^y+x^-y=2根号2,则x^y-x^-y等于
1、x(x-y)(x+y)-x(x+y)^2
已知x^2+y^2-6x-8y+25=0,求分式y/x - x/y的值
已知x^2+y^2-6x-8y+25=0 求y/x-x/y的值
已知x,y满足x^2+y^2-6x+8y+25=0,求y^x的值
已知x平方+y平方+6x-8y+25=0,求y/x+x/y-2的值.
x>0,y>0,x+y=1,求8/x+2/y的最小值?
2x+3y-1=y-x-8=x+6 ,y=?
已知:3x=8y.求(1)x+y/y (2)2x+3y/x-2y