Why does $0/0$ have to be undefined? [duplicate]

Why can't it no be $\pm$ Infinity?

If $x/1$ is $x$ then $x/0$ should be $\pm$ Infinity.

marked as duplicate by mdp, user99914, drhab, vonbrand, Matthew TowersMay 13 '14 at 11:15

• Down vote cause you dont know? – user41758 May 13 '14 at 11:03
• You cannot divide by zero. Zero does not have a multiplicative inverse in the field of rational numbers (or real numbers, or complex numbers, or any field), because the existence of such an inverse would be inconsistent with the field axioms. – Paulistic May 13 '14 at 11:06
• Did you check math.stackexchange.com/questions/556957/… ? – user99914 May 13 '14 at 11:07
• @Paulistic ..Kind of like infinity? – user41758 May 13 '14 at 11:13
• Other question does not answer why you cant use +- Infinity instead of undefined – user41758 May 13 '14 at 11:18