Correct. You applied the rules of exponents correctly to simplify this expression. $\displaystyle{{2}}^{{9}}\cdot{{8}}^{{-{{2}}}}\cdot{{4}}^{{8}}={{2}}^{{9}}\cdot{{\left({{2}}^{{3}}\right)}}^{{-{{2}}}}\cdot{{\left({{2}}^{{2}}\right)}}^{{8}}={{2}}^{{9}}\cdot{{2}}^{{-{{6}}}}\cdot{{2}}^{{16}}\usepackage{cmbright}\Huge\$ , which simplifies to $\displaystyle{{2}}^{{19}}\usepackage{cmbright}\Huge\$ .