A sphere has a radius of 4x + 4. Which polynomial in standard form best describes the total surface area of the sphere? Use the formula S = 4r^2 for the surface area of a sphere.

Question

anonymous · Answer

Please Help, I will give you a medal!

stamp · Answer

$$r=4x+4=4(x+1)$$$$S=4r^2$$Plug in r and simplify.

anonymous · Answer

4x^2+4 ? That doesn't seem right

stamp · Answer

$$r=(4x+4)$$$$S=4r^2$$$$S=4(4x+4)^2$$

stamp · Answer

Pay attention to your properties of substitution, and order of operations.

anonymous · Answer

64x^2+64 still doesn't seem right

anonymous · Answer

@stamp you have the formula for the surface area wrong.

SA = (4)(pi)(r^2)

Substituting,

SA = (4)(pi)(4x + 4)^2

stamp · Answer

@tcarroll010 I am using the equation given to me by the op.

anonymous · Answer

What is the "op"?  Whatever the "op" is, it/he/she is wrong.  You left out :

$$\Huge{\pi}$$

anonymous · Answer

64(pi)x^2 + 128(pi)x+ 64(pi)

stamp · Answer

@tcarroll010 op = original poster, the person who created the thread.

anonymous · Answer

Then correct the formula.  Don't use an incorrect formula.  It will lead to incorrect results.

anonymous · Answer

Stamp, aren't you the one who replied the first equation?

stamp · Answer

@tcarroll010 Well that is why we have you, friend. And I did not realize it was the incorrect formula, I normally reserve for OP the job of accurately providing the given resources required to solve a problem. Anyway, ya'll got this handled.

anonymous · Answer

So, if the formula:

SA = (4)(pi)(r^2)

is used for the surface area of a sphere, we can substitute:

SA = (4)(pi)(4x + 4)^2

and then simplify.

anonymous · Answer

I got it now

anonymous · Answer

That's a good thing.  Nice working with you, good luck in all of your studies and thx for the recognition! @ballerina789

anonymous · Answer

thanks. Your welcome