Thread: Solving for a variable fraction, multiplied by a non variable.

Okay, so I'm working on through my homework and I get this question:
and I need to solve for N.

The answer is

Now, I think that one of the first things I want to do is to multiply both sides by N to try and clear the fraction. This is where I get confused. Does it become something like this or am I not even doing that step correctly?

You multiplied by N both sides so you will "cut" the N on right side of the equation.

Now divide the equation by I and you will have the answer.

Regards.

Originally Posted by Kaziel

Okay, so I'm working on through my homework and I get this question:
and I need to solve for N.

The answer is

Now, I think that one of the first things I want to do is to multiply both sides by N to try and clear the fraction. This is where I get confused. Does it become something like this or am I not even doing that step correctly?

1. The first step is OK:



Now cancel the N at the RHS so you don't have any Ns there.

2. Now divide the complete equation by I and you'll get the given result.

I see what I was doing wrong. I was forgetting that essentially looks like

With that in mind, an alternate way of writing would be: which would make this the same as . That's easier for me to visualize. I got it now! Oi, don't I feel embarrassed...

Thanks for the help folks.

As a small note, you may need to justify the fact that you can divide by I on both sides of the equation. In order to do this, you must be sure that I is not zero.