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

[Femme_physics]

I appear to be getting two sides with the same unknown. Does it mean I'm screwed and can't solve it in terms of "r"?

http://img716.imageshack.us/img716/4409/image2011121500032.jpg

 

[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'

 

[Doc Al]

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'

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

 

[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!

 

[Doc Al]

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

Yeah, I know.

 

[mtayab1994]

Is that a Pi or an r?

 

[Mark44]

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

 

[Mark44]

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.

 

[HallsofIvy]

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