How do we solve this?

Answer:
[tex] = - \frac{1}{36(6x + 1) ^{6} } + c[/tex]
Answer:
[tex]-\frac{1}{36\left(6x+1\right)^6} +C[/tex]
Step-by-step explanation:
we're going to us u substitution
[tex]\int (6x+1)^-7 dx[/tex]
[tex]u=6x+1[/tex]
[tex]\int\frac{1}{6u^7} du[/tex]
take out the constant, [tex]\frac{1}{6}[/tex]
[tex]\frac{1}{6}[/tex] · [tex]\int u^-7du[/tex]
next use the power rule, [tex]\int x^adx=\frac{x^{a+1}}{a+1},\:\quad \:a\ne -1[/tex]
[tex]\frac{1}{6}\cdot \frac{u^{-7+1}}{-7+1}[/tex]
simplify by substituting [tex]6x+1[/tex] for [tex]u[/tex]
[tex]\frac{1}{6}\cdot \frac{(6x+1)^{-7+1}}{-7+1} = -\frac{1}{36\left(6x+1\right)^6}[/tex]
add a constant, [tex]C[/tex]
[tex]-\frac{1}{36\left(6x+1\right)^6} +C[/tex]