Question

Create a formula for "a pizza delivery driver charges a flat $4 pickup fee plus $2 for every mile driven. If you measure the number of miles driven, the total charge increases by the same $2 for each additional mile; starting charge is $4 before any miles are driven. Thus the total fare grows linearly with miles traveled: each extra mile adds a constant amount to the cost."

Answer 1

Let m be the number of miles driven (m ≥ 0). The total charge T in dollars is

T(m) = 4 + 2m.

This is a linear function with slope 2 (each extra mile adds $2) and y-intercept 4 (the $4 pickup fee). For example, T(0)=4, T(5)=4+2·5=14.