There are several ways to do it, but DON'T just underline a greater than or
less than symbol. That can give you problems later.
The wayI always use is Insert - Symbol. Then, with the font set to "Normal
Text" and the subset set to "Mathematical Operators," you should see both the
≤ and the ≥ symbols. Select the one you want and click "Insert."
Another way to do it is to type 2264 and then Alt-X for the less than or
equal to or type 2265 and Alt-X for the greater than or equal to.
I hope this helps.
Fred