Can someone me with this problem ?

Which expresions are equivalent to the one below? check all that apply. 5x

Fanny mendelssohn manages all the magazines and paperback books at a local grocery store. she prices many paperbacks to sell at $7.99. the cost to the store is $5.29. what is the markup rate on a paperback book, based on its cost?

Atriangle has a side lengths of 18cm, 80 cm and 81cm. classify it as acute obtuse or right?