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9 - 9 + 1 = 1

9 - (3/3) + 1 = 9

It's been a while since I had you use math, but I think the answer is correct.

After the "hahaha", I looked for the trap ... and being in my bed thinking (I did not think it 2 hours), I came to mind a vision regarding that mathematical formula, a detail that I had recorded at the beginning, but I also ignored the observed: there is a slight upward shift of the sign "division."
So: 9 - (3/1) / 3 + 1 = 9

Answer not correct my friend 😜

Well, would be interesting to know that the answer should be. If you say it's -1, then I'll dispute that.