Coffeeman, It's not exactly intuitive. If the computer guys here got the detailed answers to their tractor questions that they give to posting questions, they'd spend more of their time staring at their tractors than running them.
I'm not a computer guy( my logon id is from my 1943 Caterpillar D7 cable dozer), I fumble thru it. I first copy & paste the carry over text into the reply block. then..
At the extreme top right above the reply block you'll see 'Markup in your posts". Click on that. Scroll to next to last FAQ & click on it. There are several "How do I make..." selections. I copy & paste the formula into the reply block. Then I cut & paste or insert the text over the word "text" in the formula. I do the same with links, paste the link & formula, then overlap them.
I'm showing my ineptatude here, it's better than getting hollered at by moderators for excessively long links, etc. Hope this helps. Maybe a computer guy can suggest a less complicated way. MikeD74T