(63 2/3 + 3 1/8 ) - (13 -10 5/9) =
= ( 63 16/24 + 3 3/24 ) - 2 4/9 =
= 66 19/24 - 2 4/9=
= 66 57/ 72 - 2 32/72 =
= 64 25/72
по действиям:
1) 63 2/3 + 3 1/8 = 63 16/24 + 3 3/24 = 66 19/24
2) 13 -10 5/9 = 3 -5/9 = 2 4/9
3) 66 19/24 - 2 4/9 = 66 57/72 - 2 32/72 = 64 25/72