Question

A cylinder has a radius of 4x + 2 and a height of 5x + 4. Which polynomial in standard form best describes the total volume of the cylinder? Use the formula V = r²h for the colume of a cylinder.. . A) 80x³ + 144x² + 84x + 16. B) 80x³ – 144x² + 84x + 16. C) 80x³ + 144x² + 84x – 16. D) 80x³ + 144x² – 84x + 16

Answer 1

V = r^2*h
V = (4x+2)^2*(5x+4)
V = (16x^2 +16x +4)*(5x+4)
V = (80x^3 +80x^2 +20x + 64x^2 +64x +16)
V = 80x^3 + 144x^2 + 84x +16

Answer 2

area of the base = pi*(4x+2)^2 = pi*(16x^2 +16x +4)

volume of cylinder = pi*r^2 *h

V = pi *(16x^2 +16x +4)(5x+4) = pi*(80x^3 +80x^2 +20x +64x^2 +64x +16) =

= pi*(80x^3 +144x^2 +84x +16)

than we consider it without pi so result choice A. is right sure

hope helped