Question

24π=2π(r^2+r) solve for r​

Answer 1

r=3

Explanation:

24π=2π(r^2+r)

Divide each side by 2 pi

24π/2π =2π/2π(r^2+r)

12 = r^2 +r

Subtract 12 from each side

12-12 = r^2 +r -12

0 = r^2 +r -12

Factor

What number multiply to -12 and add to 1

4*-3 = -12

4-3 = 1

0= (r+4) (r-3)

Using the zero product property

r+4 =0 r-3 =0

r+4-4 =0-4 r-3+3=0+3

r = -4 r = -3

Assuming r is the radius, r must be positive

r =3