第1个回答 2018-12-20
In[1]:= Maximize[{5 x1 + 12 x2 + 4 x3, x1 + 2 x2 + x3 <= 5,
2 x1 - x2 + 3 x3 == 2, x1 >= 0, x2 >= 0, x3 >= 0}, {x1, x2, x3}]
Out[1]= {141/5, {x1 -> 9/5, x2 -> 8/5, x3 -> 0}}
得到一解:最大值为141/5。然后用此值代进去求解:
In[2]:= Solve[{5 x1 + 12 x2 + 4 x3 == 141/5, x1 + 2 x2 + x3 <= 5,
2 x1 - x2 + 3 x3 == 2, x1 >= 0, x2 >= 0, x3 >= 0}, {x1, x2, x3}]
Out[2]= {{x1 -> 9/5, x2 -> 8/5, x3 -> 0}}
结果只有一组,也说明上述解是唯一解。