Understanding Basic Algebra: Rearranging Equations and Solving for Variables

[AstroIreland]

Homework Statement

I have a very simple question I am having problems with.

Homework Equations

n= C/V

The Attempt at a Solution

Hey guys,

This is a very simple equation indeed. I am a mature student and starting up in physics.
My mathematics is terrible. So please don't laugh. I can seem to integrate and differentiate but for some reason, I have forgotten something really really really stupid.

I rearranged the above formula earlier and to solve for v and I came up with Cn=V.

I don't know why I am doing that and this, I had no problem before.

So my question is, when changing sides of an equation, how do I know which to move from one side to the other and in what order.

Do i start with numerator or denominator. And if so, what order.

I have exams coming up and I am in a divorce currently and really really simple stuff has completely slipped from my brain. For obvious reasons, I can't ask this question at my university.

I am in a bit of a panic.

 

[Chestermiller]

Multiply both sides by V, and then divide both sides by n.

 

[AstroIreland]

Multiply both sides by V, and then divide both sides by n.

Cheers, but why do you move the v first and not the C?

Is it because its the bigger number or do you always move the denominator first and solve in more steps?

 

[AstroIreland]

like why wouldn't you just move the C first??!

Thanks

 

[AstroIreland]

And say for example I am using the Snells law formula where there is a fraction on each side of the equation.
How do I know when changing sides whether to add to the numerator or denominator? thanks.

 

[AstroIreland]

No worries, cross multiplication was what I am looking for.

Can you believe i made it to second year astro in the top 50 uni's in the world?!

Jeeze... exams do funny things to you.

Thanks mate.