Sorry about the photo the question is there

Cam bought some used books for $4.95. he paid $0.50 each for some books and $0.35 each for the others. he bought fewer than 8 books at each price. how many books did cam buy?

Add the two expressions 3.8b - 7 and 2.9b + 9 enter your answer in simplified form

Your car's gasoline tank holds 18 gallons of gasoline. on a trip in canada, the tank is one-quarter full. you want to fill the tank. how many liters of gasoline are needed to fill the tank