solve. 4+3x

You do this problem just the same way that you would do it if it were not an inequality.  What that means is that you need to get the x term on one side by itself and then simplify it down to where it is just x (instead of 3x).

So, what you do first is to subtract 4 from both sides.  Then you get

3x < 24

So then you divide both sides by 3 and you get

x < 8

And that is your answer.  Plug in a number to check and see if it's right.  We'll choose 7.

4 + 3*7 < 28

4 + 21 < 28

25 < 28

True.  So numbers less than 8 make the inequality true.

Now we'll try a number bigger than 8.

4 + (3*9) < 28

4 + 27 < 28

Not true.  So numbers bigger than 8 make the statement false.