KLM and KBC what is the value of x

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

Ineed in figuring out this problem.

Richard save $32 in march he saved $48 in april and $38 in may then richard spent $113 on a keyboard how much money does richard have left