Answer:
A. -12
Step-by-step explanation:
A graph shows the vertices of the feasible region to be (0, 6), (3, 0) and (0, -3). Of these, the one that minimizes f(x, y) is (0, -3). The minimum value is ...
f(0, -3) = 3·0 + 4(-3) = -12
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<em>Comment on the graph</em>
Here, three regions overlap to form the region where solutions are feasible. By reversing the inequality in each of the constraints, <em>the feasible region shows up on the graph as a white space</em>, making it easier to identify. The corner of the feasible region that minimizes the objective function is the one at the bottom, at (0, -3).