Equations & Transposition

Hey I was working on chapter questions and I am stuck on a few questions, any help I would greatly appreciate it. Please show work.
NOTE: THIS IS NOT HOMEWORK, OPTIONAL QUESTION BUT IF I WERE TO SEE THIS ON A TEST I WOULD LIKE TO KNOW HOW TO SOLVE IT.

Find A

CBE/AFG=sq root B

N=6A^2/B^3

I=AB/Ar+R

Thanks!!!

1.) CBE / AFG = √B
CBE = √B(AFG)
AFG = CBE / √B
A = (CBE / √B) / FG
A = (CBE / √B)(1 / FG)
A = CBE / FG√B
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2.) N = 6A² / B³
6A² = B³N
A² = B³N / 6
A = √(B³N / 6)
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3.) l = AB / Ar + R
l(Ar + R) = AB
Arl + Rl = AB
Arl - AB = - Rl
A(rl - B) = - Rl
A = - Rl / (rl - B)
A = Rl / (B - rl)
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