I came across this question and was able to calculate the lowest possible value of the equations that is (-1,0) for the first one and (0.75,-2.5) for the second one. After that i was confused which points to consider as the value of Qty A and Qty B what should be the rule to thumb to follow in this kind of situation? in the solution greg considers 0 for Qty A and 0.75 for Qty B.
