consider the following mathematical model: Min Z = f 1 (x 1 ) + f 2 (x 2 ) subjet to 1. either x 1 = 3 or x 2 = 3 2. At most one of the following...

consider the following mathematical model:

Min Z = f1(x1) + f2(x2)

subjet to

1. either x1 >= 3 or x2 >= 3

2. At most one of the following inequalities holds:

2x1 + x2 >= 7

x1 + x2 >= 5

x1 + 2x2 >= 7

3. |x1 - x2 | = 4

4. x1 >= 0, x2 >= 0, where f1(x1) = { 7+ 5x1 if x1 > 0, or f1(x1)= 0 if x1 = 0

f2(x2) = { 5 + 6x2, if x2 > 0, or f2(x2) = 0

Formulate this problem as an MIP problem.