若变量X、Y满足{x+y+2≤0,x-y+4≥0,y≥a},若2x-y的最大值为-1.则a?

变量x,y满足x-2y=0,x 设变量x,y满足x+y 若变量x,y满足约束条件｛y=0,x-y-2 若变量x,y满足约束条件｛y=0,x-y-2 若变量x,y满足约束条件{x>=-1;y>=x;3x+2y 若变量X、Y满足{x+y+2≤0,x-y+4≥0,y≥a},若2x-y的最大值为-1.则a? 若变量x y满足约束条件x+y≤5 x-y≤-1 x≥0 则z=3x-2y的最小值 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 若变量x y满足约束条件{x+y 设变量x.y满足条件3x+2y 变量x,y满足约束条件,x+y>=3,x-y>=-1,2x-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? 数学不等式：变量x,y满足约束条件「x-y≥0,x+y≤0,x+2y≥1」,求z=5x+y的最大值变量x,y满足约束条件「x-y≥0,x+y≤0,x+2y≥1」,求z=5x+y的最大值,有图最好!变量x,y满足约束条件「x-y≥0,x+y≤1,x+2y≥1」， 已知变量x,y满足条件{x 已知变量x,y满足约束条件x+2y-3=0,y-1 已知变量x,y满足约束条件x+2y-3=0,y-1