0,66: 0,666: 0,667: 0,67 .
1/8 x - 2/3 x + 1/2 x = -5/18
3/24 x - 16/24 x + 12/24 x = - 5/18
-1/24 x = - 5/18
x = 5/18 × 24
x = 20/3
x = 6 2/3