# Integration by substitution, but I cannot see how

I am trying to find an indefinite integral. The question suggests that it can be solved with integration by substitution, but I cannot see how. Multiplying out the brackets and integrating gives an eight-order result. Can anyone help here?

$$\int \left(x+4\right)\left(\frac{1}{3}x+8\right)^6\:dx$$

• Multiply and divide by $3^6$ (the one in the numerator goes into the exponent expression to cancel out the $\frac 13$). Next, put $y=x+24$. Now see what you get. – астон вілла олоф мэллбэрг Mar 6 '17 at 11:12

Isn't it natural to set $u=x/3+8$ ?
$$\int \left(x+4\right)\left(\frac{1}{3}x+8\right)^6\:dx=3\int \left(3u-20\right)u^6\:du$$