Answer:
The value of q that maximize the profit is q=200 units
Step-by-step explanation:
we know that
The profit is equal to the revenue minus the cost
we have
---> the revenue
---> the cost
The profit P(q) is equal to

substitute the given values



This is a vertical parabola open downward (because the leading coefficient is negative)
The vertex represent a maximum
The x-coordinate of the vertex represent the value of q that maximize the profit
The y-coordinate of the vertex represent the maximum profit
using a graphing tool
Graph the quadratic equation
The vertex is the point (200,-120)
see the attached figure
therefore
The value of q that maximize the profit is q=200 units