Pls solve and explain clearly

12. A spherical balloon is inflated with helium at a rate of 247- in' . How fast is the min balloon's radius increasing when the radius is 5 in? (V = =x7 ) a. 2.16 in/sec b. 0.24 in/sec c. 0.75 in/sec d. 0.08 in/sec 13. Calculate the derivative of f (x) - x -7 x + 2 a. f'(x) = 2x x - 7) - 3x (x2 + 2) (x - 7) b. f' (x ) = 3x (1 + 2) - 2x(x3 - 7) (x -7) 2x (x3 -7) -3x (x2 + 2) C. '(x ) = ( x 2 + 2 ) d. f'(x) = 3x (x +2) - 2x(x -7) 15. Calculate the slope of the normal line to the indicated curve at the given point: x -y=53 at (2, -49). a. m = -4 b. m=4 C. m= - d. m= 16. Calculate the indefinite integral: [x (9+x ) dx a. 18 (9 +x ) +c b. 18(9 +x ) +0 C. 36( 9 + x ) +0 d. 1 36 ( 9 + x ) +c 20. For the function y =12x-x , find the relative maximum, relative minimum, and inflection point. a. Relative maximum at (0, 12). No relative minimum or inflection point. b. Relative maximum at (-2, 16). Relative minimum at (2, -16). Inflection point at (0, 0). c. Relative maximum at (2, 16). Relative minimum at (-2, -16). Inflection point at (0, 0). d. No relative maximum or relative minimum. Inflection point at (0, 0)