Lisa is taking two classes at a local community college. She sets aside 21 hours for homework a week with these two classes. The two classes are 4 hours each once a week on Tuesday and Thursday. She wants to get a part-time job and ensure 8 hours of sleep each night. There are 168 hours in one week. How many hours can she work at most each week? Write and solve an inequality to determine the maximum amount of time she can work each week.

Answer 1

Lisa spends a total of 4 + 4 = <<4+4=8>>8 hours in class each week with these two classes.
She spends a total of 8 * 7 = <<8*7=56>>56 hours sleeping each week.
When you add up all of her sleep and study time, it equals 56 + 8 + 21 = <<56+8+21=85>>85 hours.
In one week, Lisa has 168 - 85 = <<168-85=83>>83 hours left for work and other activities.
Let x be the number of hours Lisa can work each week.
The inequality to represent the maximum number of hours Lisa can work is x ≤ 83.
The maximum number of hours Lisa can work is 83. Answer: \boxed{83}.