Santiago is working at his mom’s day care this summer. His mom has asked him to check out the library

Question

book sale to look for books they might be able to use in the day care. When he gets to the book sale, he
sees that hard cover books are $2.00 and soft cover books are $1.00. He picks out a variety of books and
spends $30.
A. Write a two-variable equation to represent this situation. Be sure to define the variables you use in your
equation.

Answer 1

To represent the situation with a two-variable equation, we first need to define the variables:

Let:

• \( h \) = the number of hard cover books
• \( s \) = the number of soft cover books

The cost of hard cover books is $2.00 each, and the cost of soft cover books is $1.00 each. Santiago spends a total of $30 on these books.

The equation representing the total cost is:

\[ 2h + 1s = 30 \]

This equation states that the total cost of the hard cover books (2 times the number of hard cover books) plus the total cost of the soft cover books (1 times the number of soft cover books) equals $30.