Why is a not allowed to be 0 in an exponential function?

Aretha wanted to gather data about the cost of local bowling leagues in her area. she plotted the data and determined that the average bowling league costs consist of a one-time registration fee and a monthly fee modeled by the equation y = 15x + 20. identify and interpret the y-intercept in this model. the y-intercept is 20. this is the cost per month. the y-intercept is 20. this is the cost of registration. the y-intercept is 15. this is the cost of registration. the y-intercept is 15. this is the cost per month.

Renting a room at the willow tree resort costs $125 for 2 people. each additional person is $25. write an expression that shows the cost for n extra people

Acar travels 85 kilometers per hour. what is the equivalent speed in meters per hour?