Could you explain where I went wrong with this one?

28-1-16(int) 0.8((3 + 2 ln(u))^3) du/u

Attempt:

u = 3 + 2 ln u

du = 1 / u

Therefore answer should be:

(.8 [3 + 2 ln u]^3) / 4

the ti-89 comes up with another answer when this integration is performed, which is long and bizarre.