# Integration using substitution

## Homework Statement

Integrate: 6/(1+sqrt(7x))dx

## Homework Equations

the hint was that u^2=7x

## The Attempt at a Solution

by substituting u, i got the antiderivative of (12/7)(u/(1+u))du so i substituted again and ended up getting 12/7(1+sqrt(7x)-ln(sqrt(7x)+1)) but apparently thats wrong. please help!

Last edited:

Mark44
Mentor
Assuming that your work is correct in getting to an integrand of (12/7) u/(1 + u) * du, divide u by 1 + u using polynomial long division.

wouldnt it be easier to substitute another letter like w for 1+u instead? although this did not give me the right number. i dont really get how to divide u by (1+u)

Mark44
Mentor