# Algebra - Is it possible to solve it in terms of r?

1. Dec 15, 2011

### Femme_physics

Last edited by a moderator: May 5, 2017
2. Dec 15, 2011

### BruceW

perhaps too much help there... I was thinking of writing a hint like 'what can you do to both sides to get r on only one side of the equation'

3. Dec 15, 2011

### Staff: Mentor

Oops... you're probably right, Bruce.

4. Dec 15, 2011

### Femme_physics

I can still see the original message in my email you know?

Thanks, at any rate. I seemed to have forgotten basic algebra!

5. Dec 15, 2011

### Staff: Mentor

Yeah, I know. :tongue:

6. Dec 15, 2011

### mtayab1994

Is that a Pi or an r?

7. Dec 15, 2011

### Staff: Mentor

Both $\pi$ and r are in the equation.

8. Dec 15, 2011

### Staff: Mentor

You ended up with 100$\pi$r4 = 4000$\cdot$103r.

Move everything over to one side, and take the largest common factor out of both terms. The equation should be pretty easy to solve from there.

9. Dec 16, 2011

### HallsofIvy

Staff Emeritus
Is it really "$1000\cdot10^3$". That seems a very strange thing to write. It is, of course, the same as $10^6= 1000000$.