5 8/33 - 4 18/33 + 15 28/33
Convert all fractions to have the same denominator:

5 8/33 = (5 33 + 8) / 33 = 165/33 + 8/33 = 173/33
4 18/33 = (4 33 + 18) / 33 = 132/33 + 18/33 = 150/33
15 28/33 = (15 * 33 + 28) / 33 = 495/33 + 28/33 = 523/33

Now, substitute back into the equation:

173/33 - 150/33 + 523/33
= (173 - 150 + 523) / 33
= 546/33
= 18

So, 5 8/33 - 4 18/33 + 15 28/33 = 18.