report it to the state to fix the issue

That’s why you show your work!!!

Um I would think they did since the teacher knows that they used the entirely wrong formula but still somehow managed to get the correct answer.

Dummy he did.

The harshest penalty you should have received would be zero credit for that problem only.

I had one student make an error of a factor of 1000 early in one problem, then later made another factor of 1000 error the other way such they cancelled out and bumbled into the correct answer. I awarded partial credit.

I sometimes used the wrong formula or way to work something out (not using long division etc) but still got the correct answer, they only gave me points for the answer.

You should tell the teacher, there's more than one way to skin a cat and you just discovered a new way to solve the problem.

Dumb luck =/= cheating. you can dispute this.

This is funny I did the exact same thing in high school I used the wrong formula and got the right answer I got full marks with a comment from the teacher saying they didn't know how I did it but I get full marks and he even gave me extra credit for it luckily I decided to teach preschool and kindergarten so I didn't have to deal with that happening

Next, you'll expect your teacher to believe that Australia is both a continent and a country.

I can usually get the answers, but have problems "showing my work". I can relate.