Answer:
They need to sell 3 tees, and incurred $60.
Step-by-step explanation:
What is the revenue equation? R = 20x, where x is the # of tees sold.
What is the cost equation? C = 5x + 45, where x is the # of tees sold.
Set those two equations equal, we get:
20x = 5x + 45, 15x = 45, x = 3.
3*5 + 45 = 60.
