Transposition of equation

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.

I_M = I * R_S / (R_M + R_S)


Many thanks

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.

Great. I will give it a try. Thank you.

Here is another perspective with the variables renamed, in case you were having trouble understanding them:

http://s17.postimage.org/jjg31yejz/image.png