I don’t understand what to do?

Ataxi company charges $2.25 for the first mile and then $0.20 per mile for each additional mile, or f = $2.25 + $0.20(m - 1) where f is the fare and m is the number of miles. if juan's taxi fare was $6.05, how many miles did he travel in the taxi? if juan's taxi fare was 7.65, how many miles did he travel in taxi

The number of fish in a lake can be modeled by the exponential regression equation y=14.08 x 2.08^x where x represents the year

How is working backward similar to solving an equation?