An internet service provider charges $18 per month plus an initial set-up free. once customer paid a total of $81 after two months of service. write an equation for this situation.

Noel is hoping to make a profit (in $) on the school play and has determined the function describing the profit to be f(t) = 8t – 2654, where t is the number of tickets sold. what does the number 8 tell you?