Answer:
y = 13.50x + 20
y = 17x + 6
The cost is the same after 4 hours.
Step-by-step explanation:
I don't really know what to say except you just have to replace x with 4 and then work it normally from there.
How much dose it cost per pound?
Answer:
The price of each book without sales tax
Step-by-step explanation: