Respuesta :

9514 1404 393

Answer:

  x = 9 cm

Step-by-step explanation:

The formula for the surface area of a cylinder can be written as ...

  SA = 2πr(r +h) . . . . . where r is half the diameter, and h is the height

For the given cylinder, we have ...

  972π cm² = 2π(x)(x+5x) = 12πx²

Dividing by 12π gives ...

  81 cm² = x²

Taking the square root, we have ...

  9 cm = x