Correct. The distributive property gives you $\displaystyle{2}{\left({4}{p}+{1}\right)}={2}{\left({4}{p}\right)}+{2}{\left({1}\right)}={8}{p}+{2}\usepackage{cmbright}\Huge\$ . The missing term is $\displaystyle{8}{p}\usepackage{cmbright}\Huge\$ .