Azul bought 10 reams of paper at the store for a total of 84$. The tax was on the purchase was 4$. What was the cost of each ream? Which equation could be used to represent this situation?
A.10r-84=4
B.10r-4=84
C.10r+4= 84
D.4-10r=84
A.10r-84=4
B.10r-4=84
C.10r+4= 84
D.4-10r=84