I need help with this math question

Adepartment store purchases screen-printed t-shirts at a cost of $5 per shirt. they mark up the price 150% (making the selling price 250% of the store's purchase price) and put them on the sales floor. every month that a t-shirt doesn't sell, the store reduces the selling price by 25%.

What can you determine about the solutions of this system

In which direction does the left side of the graph of this function point? f(x) = 3x3 - x2 + 4x - 2