If you would like to solve 3/(8j) = 6 for j, you can do this using the following steps:
3/(8j) = 6
3 = 6 * 8j
3 = 48j
j = 3/48
j = 1/16
If you would like to solve (3/8) * j = 6 for j, you can do this using the following steps:
(3/8) * j = 6
j = 6 * 8/3
j = 16