设x+2y=2,求z=2^x+4^y+1的最值
设x+2y=2,求z=2^x+4^y+1的最值
设X+Y+Z=0求X^3+X^2Z-XYZ+Y^2Z+Y^3的值
16.设x+y+z=3y=2z ,求x/(x+y+z)的值5.7
已知x+y+z=1,求3x^2+4y^2+5z^2的最值
设Z=2y-2x+4,求z的最大值和最小值,使x,y满足,0《x《1,《0y《2,2y-x》1!
设x+y+z=11求函数u=2x*x+3y*y+z*z的最小值
已知x::y:z=3:4:5,(1)求x+y分之z的值;(2)若x+y+z=6,求x,y,z.
设K法解, 已知x : y : z =3 : 4 : 5 且2x+3y+z=46,求x+y+z的值
已知X、Y、Z满足2X-Y+4Z=8(1);X-2Y-Z=7(2)求X-Y-Z的值
1 已知想x,y,z满足2x-y+4z=8,x-2y-z=7,求x-y+z的值
设实数x,y,z满足x+y+2z=6,求的x*x+y*y+z*z最小值,并求此时x,y,z的值.
设xyz不 等于0,且2x-y+z=0,x+2y-5z=0,试求代数式(x-y)/(y+z) 的值