x-1 2/5):10+7 5/12=9
(x-1 2/5):10=9-7 5/12
(x-1 2/5):10=8 12/12-7 5/12
(x-1 2/5):10=1 7/12
x-1 2/5=19/12*10
x=190/12+7/5
x=95/6+7/5
x=475/30+42/30
x=517/30
x=17 7/30
