The word "zero" has many synonyms: nothing, nil, none, naught/nought, zilch, nix, zip, nada and my personal favorite, diddly-squat.
Yes, but it is not reduced. It reduces to 0.
0/5 = 0
Infinity... 5 over 0 will be represented as 5/0 Any number divided by 0 results in infinity
-5, 5
No.
No.
1 - 1 = 0
-45 over 9 = -5 -5 plus 5 = 0 QED -45 over (9 plus 5) is a different matter and = -3.2143.
0.0 is.
5 or 5 0/5. They are equal.
0 divided by anything (other than 0) is 0.
5/9 as a decimal is 0.'5' recurring '5'