The original 24 m edge length x of a cube decreases at the rate of 5 m/min.
a. When x = 5 m, at what rate does the cube's surface area change?
b. When x = 5 m, at what rate does the cube's volume change?
a. When x = 5 m, the surface area is changing at a rate of m^2/min.
(Type an integer or a decimal.)