Answer:
7/18
Step-by-step explanation:

7 is prime, so this can not be simplified further (since 18 is also not divisible by 7).
Answer:
279936
Step-by-step explanation:
Hope this helps!
Answer:
$1.89 per used book
Step-by-step explanation:
Divide the total price ($9.45) by the amount of items (5) and you get the unit price of $1.89 per item