Mr. Dionne is the band director at school. He asked students to record how long they have played an instrument. The dot plot shows data he has recorded. What unit of measure is used in the study?

A. Number of observations

B. Number of instruments

C. Number of students

D. Years

Arestaurant needs to buy thirty-seven new plates. if each box has five plates in it, how many boxes will they need to buy?

You eat 8 strawberries and your friend eats 12 strawberries from a bowl. there are 20 strawberries left. which equation and solution give the original number of strawberries?

Prove (a) cosh2(x) − sinh2(x) = 1 and (b) 1 − tanh 2(x) = sech 2(x). solution (a) cosh2(x) − sinh2(x) = ex + e−x 2 2 − 2 = e2x + 2 + e−2x 4 − = 4 = . (b) we start with the identity proved in part (a): cosh2(x) − sinh2(x) = 1. if we divide both sides by cosh2(x), we get 1 − sinh2(x) cosh2(x) = 1 or 1 − tanh 2(x) = .