Question

solve the integral x/(3x+5)

Answer 1

Use a substitution \(u=3x+5\), this is one way.

Answer 2

wont work !!!

Answer 3

you will still have x's left ...

Answer 4

solve for x

Answer 5

what do you mean solve for x ?

Answer 6

\[u=3x+5 \implies x=\frac{1}{3}(u-5) \implies dx=\frac{1}{3}du.\]

Answer 7

mr math is writing it now i am sure, but solve
\[u=3x+5\] for x

Answer 8

and then ? i tried polynomil division but couldn't do it ...

Answer 9

Using the substitution, your integration becomes:
\[\frac{1}{9}\int \frac{u-5}{u}du.\]
But \(\frac{u-5}{u}=1-\frac{5}{u}\). You should be able to take it from here.

Answer 10

Is that good enough?

Answer 11

thank you !!! =]

Answer 12

Glad to help :-)