Problems 7-18
Copy down the problem as you see it in the book, and then carry out the order
of operations as described by the first 
sign in this
section. You will find it easier if your organize your work as shown here
(for Problem 16a):
8 + 2(3 + 12) - 5 * 3 = 8 + 2(15) - 15
= 8 + 30 - 15
= 23