n is a placeholder for a number. In this case, it is 4
We will replace every copy of 'n' with '4' and then simplify
So n+8 turns into 4+8 which simplifies to 12
Is 12 less than or equal to 13? Yes it is. Specifically it is less than 13. So n = 4 is part of the solution set.
Here is how you'd write it all out using algebra
[tex]n+8 \le 13[/tex]
[tex]4+8 \le 13[/tex]
[tex]12 \le 13[/tex]
The last inequality is true so the first inequality is true when n = 4. This is another way to see that n = 4 is a solution.
