You buy the same number of brushes, rollers, and paint cans. write an expression in simplest form that represents the total amount of money you spend for
painting brush cost $3.99, paint cost $21.79 and paint roller cost $6.89

If you buy ' N ' of each item, then you'll pay  3.99N  for brushes,
21.79N  for cans of paint, and  6.89N  for rollers.

The question assures us that you bought the same number of
each item.  So your total bill at the hardware store checkout is

                      3.99N + 21.79N + 6.89N

                 =  N (3.99 + 21.79 + 6.89)

                 =        32.67 N .