please answer the following

99 10. A mass of 1 slug (creating a force of 32 lb. ) is attached to a spring whose constant is 5 1b/ft. Initially, the mass is released 1 foot below the equilibrium position with a downward velocity of 5 ft/sec, and the subsequent motion takes place in a medium that is numerically equal to 2 times the instantaneous velocity. Find the equation of the motion if the mass is driven by an external force equal to f(t) = 12cos(2t) + 3sin(2t)