The answer is 1929.
2009 - 1929 = 80
80 minus 12.6 is 67.4
80 minus 4 is 76.
2009 minus 1970 is 39
90 - 80 = 10
-80 - 1 = -81
140 - 80 = 60
80 - 45 = 35
5000.00 minus 20% = 80% of 5000.00 = 5000.00*80/100 = 4000.00
173 - 90 = 80
200
an A minus obviously ranges from an 80 to a 84 :D