Question 846062
Use Pascal's triangle.
The coefficients would be 
{{{x^12 - 1}}}
{{{x^11 -12}}}
{{{x^10 -66}}}
{{{x^9 -220}}}
{{{x^8 -495}}}
{{{x^7-792}}}
{{{x^6-924}}}
{{{x^5-792}}}
{{{x^4-495}}}
{{{x^3-220}}}
{{{x^2-66}}}
{{{x^1-12}}}
{{{x^0-1}}}