(х - 1 2/5) : 10 + 7 5/12 = 9
(x - 1 2/5) : 10 = 9 - 7 5/12
(x - 1 2/5) : 10 = 1 7/12
x - 1 2/5 = 1 7/12 * 10
x - 1 2/5 = 15 5/6
х = 15 5/6 + 1 2/5
x = 17 7/30
(х - 1 2/5) : 10 + 7 5/12 = 9
(x - 1 2/5) : 10 = 9 - 7 5/12
(x - 1 2/5) : 10 = 1 7/12
x - 1 2/5 = 1 7/12 * 10
x - 1 2/5 = 15 5/6
х = 15 5/6 + 1 2/5
x = 17 7/30