line has the equation y=6x +b. What must be the value of b for the line to model a directly proportional relationship

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

How do you solving the solution of each system using elimination?

Two variables, x and y, vary inversely, and x=12 when y=4. what is the value of y when x=3?