Thread: Leaving single variable by itself.

I have the following equation

I=(nE)/(R+nr)

and I need to get n by itself. So far what I have done is:

I*(R+nr) = nE
IR+Inr = nE

But I don't know what to do next since everything I do doesn't help me leave n by itself (and by that I mean that there must be a single instance of n in the whole equation).

Thanks for the help.

I solved it:

I=(nE)/(R+nr)
I*(R+nr) = nE
IR+Inr = nE
Inr = nE - IR
Inr - nE = -IR
n(Ir-E) = -IR
n = -IR / (Ir - E)

n = -IR / (Ir - E)
Very good.

And if you don't want to see that negative sign in front of the IR, you can eliminate that by making it positive. Negative times negative equals positive. So you can multiply the numerator and the denominator by negative 1, like this:

n = -IR / (Ir - E) * -1 / -1
n = +IR / (-Ir +E)
n = IR / (E -Ir) -------------***