(x-1 2/5)÷10+7 5/12=9

(х - 1 2/5) : 10 + 7 5/12 = 9
(х - 1 2/5) : 10 = 8 12/12 -7 5/12
 х - 1 2/5 = 1 7/12 · 10
 х - 1 2/5 = 19/12 · 10
 х = 15 5/6+1 2/5
 х = 15 25/30 +1 12/30
 х = 16 37/30
 х = 17 7/30