设x,y满足约束条件：3x-y-6=0,x>=0,y>=0,若目标函数z=ax+by（a>0,b>0)最大值为12,求2/a+3/b的最小值.

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X,Y满足约束条件X+Y 设x,y满足约束条件x>=0 x>=y 2x-y 设x,y满足约束条件x+y>=1,x-y>=-1,2x-y 设x,y满足约束条件x+y>=1,x-y>=-1,2x-y 设变量x,y满足约束条件x-y>-1,x+y>1,3x-y 设变量x,y满足约束条件y≤x,x+y≥2,y≥3x-6,则目标函数z=2x+y的最小值 设变量x,y满足约束条件x-y>=-1,x+y>=1,3x-y 设变量xy满足约束条件x-y≥0,x+y-2≥0,3x-y-6≤0则目标函数z=2x-y设变量xy满足约束条件x-y≥0,x+y-2≥0,3x-y-6≤0则目标函数z=2x-y的最小值为（ ）. 设实数x,y满足约束条件：x>=2;y>=x;2x+y 设变量x,y满足约束条件y>=0.x-y+1>=0.x+y-3 设x y 满足约束条件 x≤0 x≤y 2x-y+1≥0 则z=3x+2y的最大值 设x,y满足约束条件:x-y+1≥0,x+y-1≥0,x≤3.则z=2x-3y的最小值为? 设x,y满足约束条件{x-y+5≥0,x+y≥0,x≤3}求z=(x+1)^2-y^2的最大值? 设x,y满足约束条件x≦y,x+2y≦3,x≧0,则z=2x-y的最大值为