Question

SOMEONE PLEASE HELP, I'M SO CONFUSED.

A sphere has a radius of 2x + 5. Which polynomial in standard form best describes the total surface area of the sphere? Use the formula S = 4π r² for the surface area of a sphere.

A. 16πr² + 80πx + 100π
B. 16πx² - 80πx - 100π
C. 16πx² + 80πx + 100π
D. 16πx² - 80πx + 100π

Answer 1

Taking this step by step:

We can start by squaring 2x+5. Expanding (2x+5)(2x+5), we get:

`4x^2+20x+25`

Multiplying by 4pi, we then get:


`16x^2\pi + 80x\pi + 100\pi`

This is equal to option C.