Answer:
21 is A
22 is B
Explanation:
51 / 3 = 17, which is the cost of 1 hour. That means, in order to find the charge (y), you need to multiply the # of hours (x) by 17. Equation A represents this correctly.
Now that we know this, for question 22, if someone rented a machine for 3.5 hours, to find the charge, multiply 3.5 by 17. This gives you 59.50.