What is the slope of this line?

The late fee for library books is $2.00 plus 15¢ each day for a book that is late. if maria’s fee for a late book was $3.20, write and solve a linear equation to find how many days late the book was.

Find the average speed of a rabbit that runs a distance of 22 m in a time of 1.8 s .

Adam used 1072.4 gallons of water over the course of 7 days. how much water did adam use, on average, each day?