PLZ HELP QUICK WILL MARK BRAINLIEST

Step-by-step explanation:

12.

the formula for the volume of a cone is V=1/3hπr²

549.5 = 1/3(21)(3.14)(x)^2

549.5 = 7(3.14)(x)^2

549.5 = 21.98(x)^2

549.5 = 21.98(x)^2

divide by 21.98 on both sides

25 = (x)^2

sqrt 25 = sqrt x^2

5 = x

13.

the formula for the volume of a sphere is V=4/3πr^3

v=4/3(3.14)9^3

v=4/3(3.14)729

v=(4.186)729

v=3052.08

14.

the formula for the volume of a sphere is V=4/3πr^3

523=4/3(3.14)r^3

523=4/3(3.14)r^3

523=(4.186)r^3

divide by 4.186 on both sides

124.92=r^3

cube root on both sides

4.998=r

round

5=r

Please mark brainliest this took me a while

this may not be at all, but i use the same website you're using for school, and if i'm stuck doing one of these i try to look for it on the section.