Question 52640
  
  Apply the formula {{{a^3-b^3 = (a-b)(a^2+ab+b^2)}}} here in your problem to factorise.
Your problem:- 
  {{{x^3-1000 = x^3-10^3}}}
  {{{x^3-10^3 = (x-10)(x^2+10x+100)}}} Answer.  
I think now it is clear to you. All the best.  May God bless you. 
  
 
gsm