Using symbols. there are 3 shelves. each shelf has 21 books. how many books are there in all?

If a =6, what is the value of 2a(3b + 5c)?

Bill works as a waiter and is keeping track of the tips he ears daily. about how much does bill have to earn in tips on sunday if he wants to average $22 a day? tips by day tips (dollars) monday tuesday wednesday thursday friday saturday $14 $22 $28 $36

The height of a flare fired from the deck of a ship in distress can be modeled by h(t)= -2(8t^2-52t-28), where h is the height of the flare above water and t is the time in seconds. a. find the time it takes the flare to hit the water.