Help Arranging Laplace Equation for Test Prep

[Patrick.Gh]

hello all. my question isn't about the solution, but more how the solution was obtained.

i have a circuit from which i obtained the following equation
Vo { 1/4000 + 1/(0.08S) + 1/(21000 + 10^9/(5S) } = 300/S

however the problem is, that i can't arrange it so that it becomes in the following form, from which i can get the solution.
Vo = 12*(21S + 20* 10^4) / {(S+10000)*(S+40000)}

if someone can help me by explaining step by step how this was done, i would be VERY grateful as i have a test coming up.
P.S: usually if the equation has 1 term in each denominator i have no problem in arranging it. its the 1/(21000+ 10^9/(5S)) that is giving me the trouble.

 

[CEL]

\frac{1}{21000 + \frac{10^9}{5s}} = \frac{5s}{21000*5s+10^9}