Question

(9 + 9x)^3 (9) dx

Answer 1

\[ \int\limits(9 + 9x)^3 (9) dx\]

u = 9 + 9x
du = 9dx

\[\int\limits (u)^3 du\]
\[= \int\limits(u)^4/4 + c\]

should = \[(9 + 9x)^4 / 4 + c\]

Answer 2

^that's right

Answer 3

:) On to the next question, thank you :D