(х - 12) : 3/8 / 0,3 * 3 1/3 + 7 = 1
(х - 12) * 8/3 / 3/10 * 10/3 + 7 = 1
8/3 х + 12*8/3 / 1 + 7 = 1
8/3 х + 32 / 8 = 1
(8/3 х + 32) : 8 = 1
(8/3 х + 32) * 1/8 = 1
8/3 х * 1/8 + 32 * 1/8 = 1
1/3 х + 4 = 1
1/3 х = 1 - 4
1/3 х = - 3
х = - 3 : 1/3
х = - 3 * 3
х = - 9.
Ответ: - 9.