Answer:
$130
Step-by-step explanation:
To find the tip you have to change the percent into a fraction first. Since percent is out of a 100, 25% is 25/100 or 1/4. Multiplying 1/4 by 520 you get 130, which is how much the coach will tip.
f(x) = 2x - 5
it would be 5,000
