设2008x^3=2009y^3=2010z^3,xyz>0,且三次根号下2008x^2+2009y^2设2008x^3=2009y^3=2010z^3,xyz>0,且三次根号下2008x^2+2009y^2+2010z^2=三次根号下2008+三次根号下2009+三次根号下2010,求x分之1+y分之1+z分之1的值.

设x.y满足条件y>=0.X-Y+1>=0.x+y-3 设x,y满足约束条件{x>=0,y>=x,4x+3y 设x,y满足约束条件x>=0 y>=x 4x+3y 设函数y=(1+x^3)^(cosx),求y' 设变量X,Y满足约束条件{X-Y+3>=0,X+Y>=0,-2 设变量x,y满足约束条件:x-y+3>=0 x+y>=0 -2 设不等式组x+y-2>=0,x-3y+6>=0,x-y 设X+Y=K,且X,Y满足不等式组 X-3Y 设y=3^x+core^x,求dy 设正实数x,y满足x^3+y^3=x-y,求证：x^2+4y^2 设实数X,Y满足2X+Y-2>=0,X-2Y+4>=0,3X-Y 设变量x,y满足约束条件x-y>=-1,x+y>=1,3x-y 设x,y是实数,且满足(x-1)^3+2008(x-1)=-1,(y-1)^3+2008(y-1)=1,则x+y= 设实数x,y满足方程组①x-y-2=0 ③2y-3 设A={(x,y)/x+y 设M={(x,y)||x|+|y| 设不等式组{x>=0,x+3y>=4,3x+y 设2x分之3x-5y=4 则y分之x=