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.
Lisa spends a total of 4 * 2 = <<4*2=8>>8 hours on her two classes.
She has a total of 168 - 8 - 21 = <<168-8-21=139>>139 hours left for sleep and work.
To get her sleep, she can sleep a maximum of 8 * 7 = <<8*7=56>>56 hours in a week.
So, she has 139 - 56 = <<139-56=83>>83 hours left for work.
Therefore Lisa can work a maximum of 83 hours each week. Answer: \boxed{83}.
To determine the maximum amount of time Lisa can work each week, let's calculate the total number of hours she has after accounting for all her commitments.
We know that there are 168 hours in one week.
First, we subtract the time she spends on sleep:
168 hours - 8 hours per night * 7 nights = 168 hours - 56 hours = 112 hours
Next, we subtract the time she spends on homework:
112 hours - 21 hours for homework = 91 hours
Then, we subtract the time she spends on her two classes:
91 hours - 4 hours per class * 2 classes = 91 hours - 8 hours = 83 hours
Finally, since she wants to have time for a part-time job, we can denote the maximum number of hours she can work as "x."
Therefore, the inequality that represents the maximum amount of time she can work each week is:
x ≤ 83 hours
Thus, Lisa can work at most 83 hours per week to accommodate her commitments.
To determine the maximum amount of time Lisa can work each week, we need to consider the time she spends on her classes, homework, sleep, and the total number of hours in a week.
The two classes are 4 hours each, once a week. So, Lisa spends a total of 4 + 4 = 8 hours on classes.
Lisa sets aside 21 hours for homework each week.
She wants to ensure 8 hours of sleep each night, so in a week, Lisa spends 8 hours x 7 days = 56 hours on sleep.
Now, let's calculate the total amount of time Lisa is already committed to:
Classes: 8 hours
Homework: 21 hours
Sleep: 56 hours
The total committed time is 8 + 21 + 56 = 85 hours.
Since there are 168 hours in a week, we can subtract the total committed time from the total number of hours in a week to find the maximum amount of time Lisa can work:
168 - 85 = 83 hours
Now, let's write an inequality to represent the maximum amount of time Lisa can work:
Let x represent the number of hours Lisa can work each week.
x ≤ 83
Therefore, the maximum amount of time Lisa can work each week is 83 hours.