You are guessing.
So if a number x is at least 5 from 13, then either
\(\displaystyle 13 - x \ge 5 \text { or } x - 13 \ge 5.\)
Do you follow that?
Now what I recommend, for any kind of inequality, is to solve the corresponding equality. So let's think about the first inequality.
\(\displaystyle 13 - x \ge 5 \iff 13 - x = 5 \text { or } 13 - x > 5.\)
The first is obvious \(\displaystyle 13 - x = 5 \implies 13 - 5 = x \implies x = 8.\)
Then
\(\displaystyle 13 - x > 5 \implies 13 - 5 > x \implies 8 > x.\)
Perfectly similar to how you solved the equality. Now put them together.
\(\displaystyle x = 8 \text { or } 8 > x \implies 8 \ge x \implies x \le 8.\)
But this is only half the problem.
Now work through \(\displaystyle x - 13 \ge 5.\)