What is the pattern in words if you get paid 15 dollars in 1 hour, 22 dollars in 2 hours, 29 dollars in 3 hours?
You can say:
You get $15 for the first hour and $7 for every next.
Or you can say:
You get $8 to get started plus $7 for every hour
You may want to translate that last stement into a lineair equation:
It tells you how
where the graph crosses the
(of course, in real life you wouldn't get paid that $8 if you made 0 hours! but this is maths)
With the equation you can easily work out your payment for any number of hours worked.