Final answer:
Jack's regular wage is $6 per hour.
Step-by-step explanation:
To find Jack's regular wage, let's assume his regular hourly wage is x dollars.
According to the given information, Jack worked for 5 hours at his regular wage, so he earned 5x dollars. He also worked for 4 hours at the overtime wage, which is $3 per hour more than his regular wage. So, he earned 4(x + 3) dollars.
Since his total earnings are $66, we can set up the equation: 5x + 4(x + 3) = 66.
Simplifying the equation, we get: 5x + 4x + 12 = 66.
Combining like terms, we have: 9x + 12 = 66.
Subtracting 12 from both sides, we get: 9x = 54.
Dividing both sides by 9, we get: x = 6.
Therefore, Jack's regular wage is $6 per hour.