The answer is 22 cm, you just add up all the sides when doing perimeter
Set up the following equations:
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:
Rebecca would need 61 pages if she used the blue book.
Solve the second equation by dividing both sides by 7:
Rebecca would need 78 pages if she used the red book.
Subtract the red book's pages from the blue book's pages:
Rebecca would need
17 more pages if she used the red book instead of the blue book.
Answer:
$7 per magazine sale
Step-by-step explanation:
1 magazine = $2
$5 per magazine
$7 per magazine sold
It would be: 567/18 = 31.5
So, she needs atleast 32 shelves....