The expression shown is the cost a customer pays for an item, where c is the cost the store pays for the item and 0.85c is the 85% price increase the store adds to the item.
Which expression is equivalent to c + 0.85c?

You coordinate volunteers for litter cleanup in local parks. your spreadsheet lists drivers and the number of seat belts in each driver’s car. the spreadsheet calculates the number of drivers (d) and the total number of seat belts (s). you want to know the maximum number of volunteers, besides drivers, that can be transported to the park in a single trip given that each person must have a seat belt of their own.