Find the circumference r=3ft use 3.14 for pi pls help

The table respent two linear functions the equation respented by the first tables is given

Which of the following is the result of expanding the series

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?