Your friend has $90 when he goes to the fair. he spends $5 to enter the fair and $15 on food. rides at the fair cost $1.50 per ride. which function can be used to determine how much money he has left over after x rides?

f(x) = 1.5x + 70
f(x) = −1.5x + 70
f(x) = −1.5x − 70
f(x) = −20x + $90

Suppose you are an avid reader and are looking to save money on the cost of books instead of paying about $20 for each book, you decide to look into purchasing a kindle for $120 you can purchase e-books for about $5 each 1. find the slope-intercept equation for the cost of the hard copy of books using x to represent the number of books 2. find the slope-intercept equation for the cost of the kindle with cost of e-books using x to represent the number of books