Consider the following minimization problem:
Min z = x1 + 2x2
s.t. x1 + x2 = 300
2x1 + x2 = 400
2x1 + 5x2 = 750
x1, x2 = 0
What is the optimal solution? Write your answer in the form : ( x1, x2, z). (For example, the expression (10, 20, 50) means that x1 = 10, x2 = 20, and z = 50).