Question

A soup can that is a cylinder has a radius of 2x-1 and a height of 3x. What is the surface area of the soup can?

Answer 1

SA = ? 
r = 2x - 1 
h = 3x 

Then, 

SA = 2π(2x - 1)² + 2π(2x - 1)(3x) 
==> 2π(4x² - 4x + 1) + 6πx(2x - 1) 
==> 8πx² - 8πx + 2π + 12πx² - 6πx 
==> 20πx² - 14πx + 2π units²