(x-1 2/5):10+7 5/12=9
( X - 1 ( 2/5 )) : 10 + 7 ( 5/12 ) = 9 ; ( X - 1 ( 2/5 )) : 10 = 9 - 7 ( 5/12 ) ; X - 1 ( 2/5 ) = 1 ( 7/12 ) * 10 ; X - 1 ( 2/5 ) = 190/12 ; X = 15 ( 5/6 ) + 1 ( 2/5 ) ; X = 15 ( 25/30 ) + 1 ( 12/30 ) ; X = 16 ( 37/30 ) ; X = 17 ( 7/30 )