Answer:
its for sure C
Step-by-step explanation:
$40/12 = unit rate simplify = 10/3
$10/3 per book
18 * 10/3 = $60 for 18 copies
Answer:

Step-by-step explanation:
In the equation: 
x's can be simplified and y's can be simplified!
Always remember that for exponents, you subtract the powers when dividing
so for x: 15-8 = 7
for y: 9-3 = 6
so the final answer is: 