a bathtub contains 45 gallons of water and the total weight of the tub

Question

A bathtub contains 45 gallons of water and the total weight of the tub and water is approximately 767.275 pounds. You pull the plug and the water begins to drain. Let v represent the number of gallons of water that has drained from the tub since the plug was pulled. Note that water weights 8.345 pounds per gallon. a. Write an expression in terms of v that represents the weight of the water that has drained from the tub (in pounds). b. Write an expression in terms of v that represents the total weight of the tub and water (in pounds). c. How much does the tub weigh when there is no water in it? d. If the weight of the tub and water is 550.305 pounds, how many gallons of water have drained from the tub?