Length contraction

[Rwingz19]

I don't know how to write math equations here, so I'll write it in words if someone can point me to a place to learn that skill on my mac I'd appreciate the help there too.

Ok, Length Contraction equation

L final = Lprime times the square root of (one minus velocity squared over speed of light squared)

My book example (Giancoli Sixth edition chapter 26 number 26-5 on page 741) cancels out the Csquared in the problem somehow. Can someone explain why?

Thanks