Express the monomial as a product of its factors.
\Express 13 as a product of 1 · 13.
\13q2r2 = 1 · 13 · q · q · r2 (Express q2 as a product of q · q)
\13q2r2 = 1 · 13 · q · q · r · r (Express r2 as a product of r · r)
The factors of 13q2r2 is 1 · 13 · q · q · r · r.