(1/6 : (3х-4)/12) - 3/8 = 1/40
(1/6 * (12 /(3х-4)) - 3/8 = 1/40
2/(3х-4) = 1/40+ 3/8
2/(3х-4) = (1+15)/40
2/(3х-4) = 16/40
2/(3х-4) = 2/5
3х-4 = 10/2
3х-4 = 5
3х=4+5
3х=9
х=3
(1/4 : (3х-2)/4)) + 2/5 = 1/2
1/4 * (4/(3х-2)) = 1/2 - 2/5
1/(3х-2) = (5-4)/10
1/(3х-2) = 1/10
3х-2=10
3х=12
х=4