xx+yy+5/4 =2x+y 求x+y的值

已知2x=3y,求xy/xx+yy-yy/xx-yy的值 已知xx+yy+4x-6y+13=0,求（xx-2x）/xx+3yy的值. xx+yy+5/4 =2x+y 求x+y的值 xx+2x+yy+6y+10=0求xx+yy的值 x,+y=5 xy=3 求xx+yy (x-y)(x+y)(xx-yy)=? 已知x(x-1)-(xx-y)=-3求xx+yy-2xy 已知x（x+1)-(xx+y)=3,求(xx+yy)/2-xy的值 x(x+1)-(xx+y)=-3,求(xx+yy)/2-xy的值 已知14(XX+YY+ZZ)=(X+2Y+3Z)^2,求X:Y:Z 若xx-2x+yy+6y+10=0 求xx-yyy的值 若xx-2x+yy+6y+10=0 求xx-yyy的值 若xx+yy-2x-6y+10=0,求分式（xx-yy）/xy的值. 知x/3=y/4=z/5,求(xy+yz+xz)/xx+yy+zz 若x-y=4,求(xx+yy)÷2-xy的值 若x-y=4,求(xx+yy)÷2-xy的值 xx-yy-x-y 因式分解 已知x+2y-5z=3;x-2y-z=-5,求xx+yy+zz的值