Answer:
x<4
Explanation:
First, you have to get rid of the 12. To do this, you subtract 12 from both sides.
3x + 12 -12 < 24 -12
After that, you should get
3x < 12
The last step is to get rid of the three, to do this you need to divide both sides by 3.
3x/3 < 12/3
Which should leave you with
x<4