For each situation, (a) write an equation in the form $y=m x+b,(b)$ find and interpret the ordered pair associated with the equation for $x=5,$ and $(c)$ answer the question. See Examples $7(b)$ and $7(c)$.
A rental car costs $\$ 50$ plus $\$ 0.20$ per mile. Let $x$ represent the number of miles driven and $y$ represent the total charge to the renter. How many miles was the car driven if the renter paid $\$ 84.60 ?$