(х-11 7/9)+5 5/18= 7 4/12

(х - 11 7/9) + 5 5/18 = 7 4/12
(х - 106/9) + 95/18 = 88/12
х - 106/9 = 88/12 - 95/18
х - 106/9 = 264/36 - 190/36
х - 106/9 = 74/36
х = 74/36 + 106/9
х = 74/36 + 424/36
х = 498/36
х = 249/18
х = 13 15/18
х = 13 5/6
проверка:
(13 5/6 - 11 7/9) + 5 5/18 = 7 4/12
(83/6 - 106/9) + 95/18 = 88/12
(249/18 - 212/18) + 95/18 = 88/12
37/18 + 95/18 = 88/12
132/18 = 88/12
22/3 = 22/3