89.99999999999999999999999999999999999999999 as a fraction

Answer 1

As written it is:

89.99999999999999999999999999999999999999999 = 8999999999999999999999999999999999999999999/10000000000000000000000000000000000000000000 = 89 99999999999999999999999999999999999999999/100000000000000000000000000000000000000000

However, if that is meant to be 89.999... with the 9 recurring, then:

89.999... = 89 9/9 = 89 + 1 = 90.

This can be seen if that is the result of addition of two recurring decimals when calculated using fractions, eg it could have been:

89.111... + 0.888... = 89.999...

= 89 1/9 + 8/9 = 89 9/9 = 89 + 1 = 90

Thus 89.999... = 90