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?

A.80pix^3+144pix^2+84pix+16pi
B.20pix^2+26pix+8pi ****
C.80pix^3+144pix^2+84pix-16pi
D.400pix^4+1040pix^3+996ix^3+416pix+64pi



My answer has the "***"by it. Please check my answer

Thanks
:)

Answer 1

Volume = Pi r^2 h
= Pi (4x+2)^2 (5x-4)
= Pi (16x^2 +16x + 4)(5x^2 - 4)

without completing the whole expansion, I know it has to start with
80Pi x^3 and end in -16Pi
The only answer that matches that is C

Answer 2

OK SO WHO IS RIGHT..

Answer 3

a
a
a
a
a
c
b
c
a
c
d
a
a
c
d
d
d
a
i know this looks unreliable i am sorry but it is reliable

Answer 4

Don't trust any answers that are just letters especially for tests...
In connexus some of the tests have different questions for everyone so it isn't reliable