设x,y满足约束条件｛x＞=0,y＞=0,x/3a+y/4a＜=1,若z=（x+2y+3）/(x+1)的最小值是1.5,则a的值是多少请说详细一点

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>=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+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 {x-y≥0,x+y≤1,x+2y≥0},则函数Z=2x+y 的最大值? 设变量x,y满足约束条件 {x-y≥0,x+y≤1,x+2y≥0},则函数Z=2x+y 的最大值? 已知x,y满足约束条件x-y+5>=0 x+y>=0 X 已知x,y满足约束条件：x-y+1>=0,x+y-2>=0,x 已知X,Y满足约束条件x-y+5>=0 x+y>=0 X 当实数x,y,满足约束条件{x>0 y>=x 2x+y+k 设x,y满足约束条件y≥0,x≥y,x+y≤1,则z=2x+y的最大值是 设x,y满足约束条件x+y>=a,x-y 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