At a department store, 5 pairs of socks cost $27.50 and 3 shirts cost $34.50. how much would it cost to buy 3 pairs of socks and 4 shirts?

Amass weighing 16 pounds stretches a spring 8/3 feet. the mass is initially released from rest from a point 2 feet below the equilibrium position, and the subsequent motion takes place in a medium that offers a damping force that is numerically equal to 1/2 the instantaneous velocity. find the equation of motion if the mass is driven by an external force equal to f(t)=cos(2t).