First distribute 6 into the first set of terms to get
6x - 18 = 3x + 8
Then combine like terms by subtracting 3x from both sides to get
3x - 18 = 8
Now, further combine like terms by adding 18 to both sides to get
3x = 26
Now solve for x by dividing by 3 to get
x = 26/3 (improper fraction)
Because 3 does not go into 26 evenly, it's in it's simplest form