Answer:
Joe earns 18x+144 dollars that week with x being the number of unknown working hours on Wednesday and Friday.
Explanation:
Joe earns $9/hour, On wednesday and friday he worked a total of 2x hours and on Tuesday and Saturday he worked a total of 16 hours. Let y be the amount of money Joe earned.
To determine how much money Joe earned we must determine how much hours he has work:
=

We can determine the amount earned from the total amount of hours work and rate of $9/hour:
