Set up the following equations:
[tex]9x = 544[/tex]
[tex]7y = 544[/tex]
x represents the amount of blue books needed, and y represents the amount of red books needed.
Solve the first equation by dividing both sides by 9:
[tex]544 \div 9 = 60 R4[/tex]
[tex]x = 60 R4[/tex]
Rebecca would need 61 pages if she used the blue book.
Solve the second equation by dividing both sides by 7:
[tex]544 \div 7 = 77 R5[/tex]
[tex]y = 77 R5[/tex]
Rebecca would need 78 pages if she used the red book.
Subtract the red book's pages from the blue book's pages:
[tex]78 - 61 = 17[/tex]
Rebecca would need 17 more pages if she used the red book instead of the blue book.
