Answer:
A
Step-by-step explanation:
The profit for selling <em>x</em> pairs of shoes is given by:
And we want to determine the number of pairs that needs to be sold in order to maximize profit.
Since the function is a quadratic with a negative leading coefficient, the maximum profit will occur at its vertex point. The <em>x-</em>coordinate of the vertex of a quadratic is given by:
In this case, <em>a</em> = -4, <em>b</em> = 32, and <em>c</em> = -39. Substitute and evaluate:
So, in order to maximize profit, only four pairs of sohoes should be sold.
Our answer is A.