How do i solve for this ,math equation? will vote best answer

will someone please explain how to solve for r in the following equation: 2 pi r 2 + 2 pi r h

also, i dont want you to just tell me could you show you you got to solve for r? thanks!

i just want r on one side and the res ton the other

I'm assuming you meant 2πr^2 + 2πrh
First, you need to set this equals to 0

2πr^2 + 2πrh = 0

2πr^2 = - 2πrh

r^2 = (-2πrh)/(2π) <======= multiply by 1/r

r = (-2πh)/(2π)

You mean 2·pi·r ^2 + 2·pi·r·h? That's the total surface area of a closed cylinder of radius r and height h.

So, you have:
SA = 2·pi·r ^2 + 2·pi·r·h
2*pi*r ^2 + 2*pi*r*h - SA = 0 (As you can see here it's quadratic, and we can use the quadratic formula)
r= [ -pi·h ±√(pi²·h²+2·SA·pi)]/ (2·pi)
--> r>0 --> r= [ -pi·h +√(pi²·h²+2·SA·pi)]/ (2·pi)

2π r^2 + 2π r h

is an expression, not an equation...you can't 'solve' for any element of an expression !

Go back to your problem and re-read it...repost with complete information !

Look up the surface area of a cylinder...

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First you multiply 2 x pi then find what to solve for r and multiply it by 2 and than
2 x pi again which you then multiply r x h

That isn't even an equation, its not equal to anything?