C=√7/LA solve for L

C=√7/LA, solve for L

C=√7/LA square both sides
C^2=7/LA cross multiply
C^2LA = 7
L=7 / [C^2A]

$C=\frac{\sqrt7}{LA}\\ CA=\frac{\sqrt7}{L}\\ \frac{1}{CA}= \frac{L}{\sqrt7}$

I will not give the last step to you. Think of it yourself. (Tips: How to make the right hand side remain only a 'L'?)