Richard can make 8 dough balls in two hours. If the amount of time is directly proportional to the number of dough balls, how many hours have passed if he made 18 dough balls?

Acable car begins its trip by moving up a hill. as it moves up, it gains elevation at a constant rate of 50 feet/minute until it reaches the peak at 2,000 feet. then, as the car moves down to the hill’s base, its elevation drops at the same rate.

Rosy waxes 2/3 of her car with 1/4 bottle of car wax.at this rate,what fraction of the bottle of car wax will rosey use to wax her entire car

Another type of subtraction equation is 16-b=7. explain how you would sole this equation then solve it.