When the internet first launched, it was slow, clogged up phone lines and was most certainly not cheap. In fact, most Internet service providers (ISP) charged a flat rate access fee that included 20 hours a month of
internet time. After twenty-hours of use, the ISP's
charged an additional per-hour fee. Suppose in 1995,
Charter charged a flat rate of $39.95 for the first twenty
hours of service and an additional per-hour charge of
$5.99.
a. How much would a Charter bill for 18 hours of
internet used be in 1995?

b. How much would a Charter bill for 28 hours of

internet used be in 1995?
c. Write an equation that could be used to model the
total price of your internet service in 1995 from Charter.