##SA=3750cm^2##
The volume of a cube is determined by the formula
##V=s^3## where ##s## is the measurement of each edge.
Since cube has six square faces each of the faces will have the area of a square which we know to be ##A=s^2##. Therefore the total surface area of a cube will be the area of a square multiplied by six (faces).
##SA=6s^2##
Solving for the length of edge (side):
##V=s^3##
##s=root(3)(V)=root(3)(15625cm^3)##
##s=25cm##
Solving for the surface area:
##SA=6s^2=6(25cm)^2##
##SA=3750cm^2##