You can
put this solution on YOUR website!250 + 2k^3x
factor the polynomial. state prime if needed.
2(125+k^3x) <---If the x is not part of the exponent, stop here.
If x is in the exponent, you have the sum of cubes that is factored by:

125=5^3 (so a=5) and k^(3x)=(k^x)^3 (so b=k^x)

Happy Calculating!!!!