Check out this kid’s explanation for why you end up with “+3x” from “-(-3x)”:
“You have -3x, so that’s three negatives, and then you have this other negative and that makes four…”
You can find this explanation at around 3:33 in the video below:
Exponents strike again!
(Or, maybe I misunderstood the kid’s explanation in the video? Lemme know if I did, please!)
Thanks to Jonathan for the submission.