20
It is now 2009, and way past February. So if we subtract, 2009 minus 1993 is 16. 2009 minus 1990 equals 19, and 2009 minus 1989 equals 20. None of these is 21.
2009 minus 1989 is 20. However, depending on when your birthday is, a person born in 1989 could be either 19 or 20 in 2009. (The older age would be for someone whose birthday had already happened since this is 2009.)
2009 minus 1970 is 39
2012 - 1989 = 23.
2017 - 1989 = 28
21
9
11000-2009=
2009 - 1820 = 189
2009 - 1992 = 17.
2009 - 1929 = 80
2009 - 1987 = 22