Question

Surface Area of Cylinder (SA)= 2pi r^2 + 2pi r h,
60pi = 2pi r (r + h)
60 pi / 2 pi = r (r + h)
30 = r ^2 + r h, sub h = 7 u get
30 = r^2 + 7r, now re-arrange to factor out and solve for r
r^2 + 7r - 30 = 0 if you factor it out, u get (r - 3)(r + 10), here are steps
r^2 + 10r - 3r - 30 = 0, factor out
r ( r + 10) - 3 (r + 10) = 0
(r - 3) (r + 10) = 0, now equating each term to 0 would yeild to
r - 3 = 0 -> r = 3 OR
r + 10 = 0 -> r = -10, Since radius cannot be negative, we discard it.

So now r = 3, we sub this to the volume of the Sphere and get this:

Volume of Sphere, V = (4/3)

Answer 1

right