Maybe reverse engineering isn’t the right term.

Brute forcing using the provided calculator and calculated guesswork till i got something that matched one of the answers.

I sometimes lost points for “something off in my formula” but the answer was correct so i passed overal.

I have a nack for “visualizing” certain math allowing for calculated guesses. I had a few instances (not on a test) where i literally just told the teacher i had not the faintest clue how to tackle the solution but it just screamed “x=3” and i was kindly told “well done, but no points without formula.