That is not a valid Roman numeral.
In todays terms: LXXXIX
89
LXXXIX is the Roman numeral for the number 89. In Roman numerals, L represents 50, XXX represents 30, and IX represents 9. When you add these values together (50 + 30 + 9), you get 89.
89 i - 1 x - 10 l - 50 50+10+10+10+(10-1) = 89
That is not a valid Roman numeral.
89
In todays terms: LXXXIX
The date 28-07-89 can be written in Roman numerals as XXVIII.VII.LXXXIX or you could write 28-07-1989 as XXVIII.VIII.MCMLXXXIX
89
LXXXIX is the Roman numeral for the number 89. In Roman numerals, L represents 50, XXX represents 30, and IX represents 9. When you add these values together (50 + 30 + 9), you get 89.
89 i - 1 x - 10 l - 50 50+10+10+10+(10-1) = 89
It's already an Arabic numeral
On Converting between Arabic and Roman Numbers we get: 89 in roman numerals is written as : LXXXIX where L=50 and X=10 and iX=9.
In todays modern notation of Roman numerals it is LXXXIX = 89 but in ancient times it would have been LXXXXV = 95
89-24 equals = 65
89 in Roman numerals is written LXXXIX