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,...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 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,...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=__________= 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 已知变量xy满足约束条件x-y＋2≦0,x≧1,x＋y-7≦0,则y/x的取值范围是 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 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 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y=1 x+y=0 x-y-2=0 则z=2x-y的最大值是多少 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