xy=15,x+y=8,x,y=?
1\x+1\y=8\x+y,则y\xy+x\xy=?
已知x的平方+y的平方-8x+6y+25=0,求(x-y+4xy/x-y)(x+y-4xy/x+y)
已知x²+y²-8x+6y+25=0,求(x-y+4xy/x-y)(x+y-4xy/x+y)
已知x-xy=8,xy-y=-9,求x+y-2xy的值
解方程x*x+xy=y+y*y
已知xy/x+y=2,则代数式3x-5y+8y/-x+3xy-y的值
帮个忙啦 已知x+y=-6 xy=8 求√y/x+√x/y
2x+8y-xy=0(x>0,y>0),求x+y的最小值
正数x,y满足xy+x+y=8,那么x+y的最小值等于?
已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值?
若x+y=-1,则x^4+5x^3y+x^2y+8x^2y^2+xy^2+5xy^3+y^4=( )
x^2+xy+x=36,y^2+xy+y=20,求x+y.