# Combining formulars

1. Dec 17, 2009

### gareth01422

Hi guys

I have question in my homework to rearrange 2 equations. see picture attached.

the equation has to have F as the subject and not have Ev in the equation.

Can someone point me in the right direction please

Gareth

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2. Dec 17, 2009

### Firelion

Hi,
I´ll help you with the first step:
Both formulars express Eph.
So you have to replace Eph in both of them and write the remaining parts as one equation.
Then the rest should be easy.
Greetings,
Firelion

Last edited: Dec 17, 2009
3. Dec 17, 2009

### gareth01422

Ah right.

Thanks for the help by the way.

I have attached my first atempt. Is this correct or could you tell me where I have gone wrong?

Gareth

#### Attached Files:

• ###### Capture2.JPG
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4. Dec 17, 2009

### Marta.92

Maybe what I'm saying is stupid, but can't you simply put them together?
By doing so, you would have:

hc*t/b= h*f
then you can transform it into

f= hc*t / (b*h)

EDIT: pardon me...I haven't seen that someone had already answered...

5. Dec 17, 2009

### Firelion

Seems perfectly correct to me.

6. Dec 17, 2009

### gareth01422

Brilliant

Thanks for the help guys.

Gareth