Plz help quick I just need the 2 answers to b

Ineed to learn how to solve this problem

Sara needs to take a taxi to get to the movies the taxi charges $4.00 for the first mile and then $2.75 for each mile after that if the total charge is $20.50 then how far was sara’s taxi ride to the movie

Asquare parking lot has 6,400 square meters what is the length in meters