77 4/15-х=59 8/9 ; 61 5/8-х=52 1/6.

77 4/15 - x = 59 8/9
x = 77 4/15 - 59 8/9
x = (77 - 59) + (4/15 - 8/9) = 18+ (12/45 - 40/45) = 18 - 28/45
х = 17 17/45

61 5/8 - х = 52 1/6
х = 61 5/8 - 52 1/6
х = 9 +(5/8 - 1/6) = 9 + (15/24 - 4/24) 
х = 9 11/24