Lenore lives in a state where sales tax is 10%. This means you can find the total cost of an item, including tax, by using the expression ( + 0.10c, where c is the pre-tax price of the item.
Use the expression to find the total cost of an item that has a pre-tax price of $84.00.

Two cars which are 40 miles apart start moving simultaneously in the same direction with constant speeds. if the speed of the car which is behind is 56 mph and the speed of the other car is 48 mph, how many hours will it take for the car which is behind to catch up the car ahead of it?