1.a
We can rewrite the given information in an algebraic expression as follows:

where x represents the number of 3/8-inch thick books. Solving for x:

We can rearrange the operation:



Then, we need 16 3/8-inch books to make a stack 6 inches tall.
1.b
To solve this exercise, we can use the same procedure as in 1.a.
0. Writing the information in an algebraic expression.

where x represents the groups of 1/2 pound.
We can convert the mixed number into an improper fraction:

2. Rewriting the operation:





We have 5.5 groups of 1/2 pounds in 2 (3/4) pounds.
Answer:
• 1.a 16
,
• 2.b 5.5