I've been struggling with this for a day, and I simply don't "get it" - this is high-school stuff, and that was a long time ago. Where am I going wrong?

The idea is to get L over on the left side of the equation.

Somehow I've managed to be involved in complex electronics and software for many years, but frankly I suck at math. I don't understand where I'm going wrong here.

Fo=1/2pi*sqrt(Lx*Cs) (this works)

L =4*pi()^2*((1/(D73*E73/1E6))^2/5e-8) (wrong!)

Various things I've tried:

To=2pi*sqrt(Lx*Cs)

To*2pi^2=4pi^2*Lx*Cs

=((d73*e73/1e6)/pi()*2)^2/5e-8

To=2*PI()*SQRT(F69*0.05) <=that works; F69=L(uH)

0=2*PI()*SQRT(F69*0.05)/To

0/2*PI()^2=(F69*0.05)^2/To

0/2*PI()^2/F69^2=0.05^2/To

To=2*PI()*SQRT(F69*0.05) <=that works; F69=L(uH)

To=2*PI()*SQRT(F69*0.05/1E12) <=that works

F=1/(2*pi()*sqrt(F66*0.05/1E12)) <=that works

F=1/(2*pi()*sqrt(F65/1E6*0.05/1E6)) <=that works

L=4*pi()^2*(L67^2/(.05/1e6)) <- garbage

L=4*pi()^2*((1/d68*e68)^2/.05) <- garbage

Where am I going wrong?