63 minus 21 is 42.
63
It is: 21 to 11
It is: 63-4 = 59
11/21 is.
(21 + 45) / (63 - 52) = 66 / 11 = 6
(5 and 1/4) - (3 and 2/3) is (21/4) - (11/3) which is (63/12) - (44/12) and that is 19/12
-52 & -11
63/11 - 310/11 = 26/11 or 24/11
91 - 63 = 28
63 - 10 = 53
100 - 63 = 37