you can prove it with math
Not a proof, just wrong. In the "(substitute 0.9999… = x)" step, it was only done to one side, not both (the left side would've become 9.99999), therefore wrong.
Not a proof, just wrong. In the "(substitute 0.9999… = x)" step, it was only done to one side, not both (the left side would've become 9.99999), therefore wrong.