4.A book club charges $10.50 to join. Members of the club pay $4.50 each for books sold by the club. Find a function that describes the sequence. Then find the total charges for a member who
buys 27 books.

1. writing an equation for an exponential function by 2. a piece of paper that is 0.6 millimeter thick is folded. write an equation for the thickness t of the paper in millimeters as a function of the number n of folds. the equation is t(n)= 3. enter an equation for the function that includes the points. (-2, 2/5) and (-1,2)