It is: 28-21 = 7
21
28 minus 27 is 1.
3x squared minus 25x minus 28
-21.. (or minus 21)
64 minus 28 is 36.
21 minus 0.5 is 20.5
63 minus 21 is 42.
2 hours 28 minutes.
Negative 37 minus 28 is -65.
-10 minus -28 is 18.
-3 minus -28 is 25
It is 21 minus 100 = -79