设X^2+2X-1=0.Y^4-2Y^2-1=0,且xy^2不等于1,求[(xy^2+y^2+1)/x]^1999的值
设X^2+2X-1=0.Y^4-2Y^2-1=0,且xy^2不等于1,求[(xy^2+y^2+1)/x]^1999的值
已知x^2-xy+3y^2=0 且xy不等于0 求x/y+y/x 的值
1若x+2y=0 ,xy不等于0,求分式 x^2+2xy / xy+y^2
1.若x分之1-y分之1=2,则求x-xy-y分之3x+xy-3y=0的值.2.设x,y为实数,且x-y=3.求x乘根号
已知5x-4y=0且xy不等于0,求x^2+y^2/x^2-y^2-x+y/x-y的值
若x-y=4,xy=1,求(-2xy+2x+3y)-(3xy+2y-2x)-(x+4y+xy)的值
已知:x-y=1,xy=-2.求:(-2xy+2x+3y)-(3xy+2y-2x)-(x+4y+xy)的值
x-y=1,xy=2.求:(-2xy+2x+3y)-(3xy+2y-2x)-(x+4y+xy)的值
.已知:x-y=1,xy=-2.求:(-2xy+2 x+3y)-(3xy+2y-2x)-(x+4y+xy)的值
已知x^2+xy-2y^2=0 (x不等于0,y不等于0),求x/y-y/x-(x^2+y^2)/xy的值
设x,y是实数,且x^2+xy+y^2=1,求x^2-xy+y^2的取值范围 用换元法计算!
设x,y是实数,且x^2+xy+y^2=1,求x^2-xy+y^2的取值范围