Ralph is an electrician. He charges an initial fee of $26, plus $31 per hour. If Ralph earned $119 on a job, how long did the job take?

3 hours

You can turn this into an equation:

F = 26 + 31t

Where F is the money Ralph earned, and t is the number of hours he worked.

Plugging in the 119 for F, we get

119 = 26 + 31t

93 = 31t

3 = t