Explanation
[tex]v=2\pi rl[/tex]Step 1
divide both sides of the equation by 2
[tex]\begin{gathered} v=2\pi rl \\ \frac{v}{2}=\frac{2\pi rl}{2} \\ \frac{v}{2}=\pi rl \\ \end{gathered}[/tex]Step 2
divide both sides by Pir
[tex]\begin{gathered} \frac{v}{2}=\pi rl \\ \\ \frac{v}{2\pi r}=\frac{\pi rl}{\pi r} \\ \frac{v}{2\pi r}=l \\ \\ l=\frac{v}{2\pi r} \end{gathered}[/tex]I hope this helps you
