Integrate :
∫(2x^2 ln8)dx
since ln8 = 3ln2 is just a number, you have
∫(2x^2 ln8)dx
= ∫2x^2*3ln2 dx
= 6ln2∫x^2 dx
= 2ln2 x^3
= ln4 x^3 + C
Maybe you had a typo, I'm guessing...
If so, recall how to do integration by parts:
∫x lnx dx
u = lnx
du = 1/x dx
dv = x dx
v = 1/2 x^2
∫u dv = uv - ∫v du, so
∫x lnx dx = 1/2 x^2 lnx - ∫x/2 dx