jcalow - you can make Rs the subject following the same steps that we laid out for you in your other post. Start by multiplying both ised by (Rm+Rs), then group the terms that have Rs in them, and simplify.
I have been having difficulty transposing equations. I posted one earlier today and people kindly helped me out with it. I think I am getting there now. Please could someone help me with the equation below, I need to make 'Rs' the subject. This should help me improve my understanding.
IM = I * RS / (RM + RS)