Answer:
$3.21
Step-by-step explanation:
This question asks for use of technology, so you can use a hand graphing calculator or the desmos website (which I used).
I have attached the screenshot of this graph. We want the maximum value on the y axis (the axis representing profit). We can see that the highest point is at (3.571, 548.214), so this is when she makes the most money.
This means that she makes the most profit at 3.571 50 cent decreases.
3.571×0.5 is a decrease by $1.7855.
This means the best price is 5-1.7855, which is 3.2145. This can be rounded to $3.21