This is a factorization of the given expression, but $\displaystyle{3}{c}\usepackage{cmbright}\Huge\$ is not the GCF. You may have thought that you needed only to factor out the different factors that occur. However, they have the variable c in common six times, so $\displaystyle{{c}}^{{6}}\usepackage{cmbright}\Huge\$ is part of the GCF, and they have the prime 3 in common two times, so $\displaystyle{{3}}^{{2}}\usepackage{cmbright}\Huge\$ or 9 is part of the GCF.