Question

Which situation can be represented by 4x + 20 = 9x ?

The price of 9 books is $20 more than the price of 4 books. What is the price of a book?
The price of 4 books is $20 more than the price of 9 books. What is the price of a book?
The price of 9 books equals $24. What is the price of a book? Joyce bought x number of $4 books and $9 books. She spent $20. How many books of each price did she buy?

Answer 1

• The price of 9 books is $20 more than the price of 4 books. What is the price of a book?

Explanation:

Target equation is

• 4x + 20 = 9x

Comparing this with situations below

The price of 9 books is $20 more than the price of 4 books. What is the price of a book?

• 9x = 20 + 4x, correct

The price of 4 books is $20 more than the price of 9 books. What is the price of a book?

• 4x = 9x + 20, incorrect

The price of 9 books equals $24. What is the price of a book?

• 9x = 24, incorrect

Joyce bought x number of $4 books and $9 books. She spent $20. How many books of each price did she buy?

• 4x + 9x = 20, incorrect