This is in Calculus and its multiple choice only. Provide necessary solution for each items. Follow the numbering. Write the correct answer if not in the choices thank you and Godbless.

10. A particle has its displacement s in meters at any time / in seconds given s = 2/- /. Find velocity at / = 4. A) -1.5 m/s C) 2.55 m/s B) 2.25 m's D) 1.75 m/s 15. The curve /(x) = (x+2) (x -2) has its relative maximum value at A) (3,25) C) (-2,0) B) (-1,-3) D) (2,0)