Need help transposing the following formula need F as the subject?

Question

the original equation is as follows:

S= 1/(1-dG) * 1/(1-tF)

thiis for exam revision so an answer as soon as.... please :D

Answer 1

Since you don't specify whether "dG" and "tF" are two variables multiplied together, or something else, I'll assume they're two variables being multiplied.

Solving
S = 1 / (1-d*G)*1/(1-t*F)
for F yields the following:
F = (1 - S + d*G*S)/(d*G*t*S - t*S)

Answer 2

ok
s*(1-dG)= 1/(1-tF)
so
1-tF = 1/ s*(1-dG)
-tF = [1/s*(1-dG)] - 1
multiply by -1/t
F=1/st(dG-1) + 1/t
or
F= 1/t [1/s(dG-1) +1]