Question 433995
We know from algebra the formula: {{{a^3-b^3=(a-b)*(a^2+ab+b^2)}}}

We apply this formula to factor our polynomial, a=x and b=10,

{{{x^3-10^3=(x-10)(x^2+10x+10^2)}}}, x^2+10x+100 is irreducible on R.

Done.