Answer:
4 classes
Step-by-step explanation:
So to solve this problem, you can make an equation. Since he makes $70 per month and $5 per class, and you're trying to figure out how many classes he has to take to get $90, you have the equation 70 + 5x = 90.
Then, you solve:
[tex]5x + 70 = 90[/tex]
subtract 70 from both sides
[tex]5x = 20[/tex]
divide both sides by 5
[tex]x = 4[/tex]
So you get that he has to take 4 classes.