The radius of a cylindrical gift box is (2x+3) in. The height of the gift box is twice the radius. What is the surface area of the cylinder? Write your answer as a polynomial in standard form.

Respuesta :

SA=2pir^2+2hpir=2pir(r+h)
h=2r=2(2x+3)=4x+6

SA=2pi(2x+3)(2x+3+4x+6)
SA=(4x+6)(pi)(6x+9)
SA=24πx²+27πx+54π