Hello Alexandra,
a)write an equation for the money earned during the first forty hours
The problem says the worker gets paid $10 per hour. That means that in an hour of work, he gets paid $10.
Since the question is asking for money earned for the first forty hour, you would multiply $10 by forty:
Pay = 10 *40
b)write down an equation for the money earned on overtime
The worker gets paid $15 for any extra time. Extra time means any hour after 40 hours. So if he worked 41 hours that week, the extra time will be 41-40 = 1 hour.
If x is the number of work hours for the week, extra time will be (x - 40) because you have to subtract 40 from the total hours to find by how much the worker went past 40 hours.
So the money earned on overtime = (how much he gets paid by overtime hour) * (amount of extra time)
---> money earned on overtime = 15*(x-40) = 15x - 600