(x 2 + 2x - 1)(x 2 + 2x + 5) find product

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?

Find the height of a square pyramid that has the volume of 32 ft.³ and a base lengthof 4 feet

You are a clerk at convenience store. a customer owes 11.69 for a bag of potatoes chips. she gives you a five dollar bill. how much change should the customer receive?