So if you take that and go backwards, and divide by 0, what is your answer? Is it 1, 2, or 3?
Since there are infinite numbers that, when multiplied by 0 give you 0, it is undefined what the answer is when you go in the reverse direction. If you allow dividing by 0, you can get nonsensical answers like 1 = 2, which is obviously incorrect.
0 * 1 = 0 0 * 2 = 0 0 * 3 = 0
Therefore 0 * 1 = 0 * 2
So if you take that and go backwards, and divide by 0, what is your answer? Is it 1, 2, or 3?
Since there are infinite numbers that, when multiplied by 0 give you 0, it is undefined what the answer is when you go in the reverse direction. If you allow dividing by 0, you can get nonsensical answers like 1 = 2, which is obviously incorrect.