One way is first to make the denominators the same, so make (3x + 2)/3 = 2*(3x + 2)/6
Now we can add the two terms: [2*(3x + 2) + 4x - 1]/6
Distribute the 2 over the first set of brackets (6x + 4 + 4x - 1)/6
Collect like terms (10x + 3)/6
or 10x/6 + 3/6
or 5x/3 + 1/2