Solve the following linear programming problems by the graphical method

Dr. Lum teaches part-time at two different community colleges, Hilltop College and Serra College. Dr. Lum can teach up to 5 classes per semester. For every class taught by him at Hilltop College, he needs to spend 3 hours per week preparing lessons and grading papers, and for each class at Serra College, he must do 4 hours of work per week. He has determined that he cannot spend more than 18 hours per week preparing lessons and grading papers. If he earns $4,000 per class at Hilltop College and $5,000 per class at Serra College, how many classes should he teach at each college to maximize his income, and what will be his income?

2 answers

so, what are the constraints, and the value to maximize?

In algebra, not words.
He can only teach 5 classes and he can't spend more than 18 hours per week preparing lessons and grading papers-Those are the constraints I think and he has to maximize his income