500 minus 279 is 221.
500 minus 315 equals 185.
3x squared minus 25x minus 28
28 minus 27 is 1.
64 minus 28 is 36.
Half of 7000 is 3500 minus 500=3000.
28% of 500 = 500 * 28/100 = 140
Negative 37 minus 28 is -65.
-10 minus -28 is 18.
-3 minus -28 is 25
1147 - 500 = 647
500 - 441 = 59