Write a system of equations to describe the situation below, solve using any method, and fill in the blanks.
Professor Olson is grading papers in the teachers' lounge. He has already finished grading 18
assignments, and is grading 8 more assignments per hour. His teaching assistant just came in
to help him. She can grade at a rate of 10 assignments every hour. At some point, they will
be finished and will have graded the same number of papers. How long will that take? How
many assignments will they each have graded?
In hours, both Professor Olson and his assistant will have graded
assignments.