Correct. $\displaystyle{y}={4}{{x}}^{{2}}-{32}{x}+{30}={4}{\left({{x}}^{{2}}-{8}{x}\right)}+{30}\usepackage{cmbright}\Huge\$ . Completing the square, you found $\displaystyle{y}+{4}{\left({16}\right)}={4}{\left({{x}}^{{2}}-{8}{x}+{16}\right)}+{30}\usepackage{cmbright}\Huge\$ . Factoring the trinomial, this can be rewritten as $\displaystyle{y}={4}{{\left({x}-{4}\right)}}^{{2}}-{34}\usepackage{cmbright}\Huge\$ . This gives you the coordinates for the vertex, which are $\displaystyle{\left({4},-{34}\right)}\usepackage{cmbright}\Huge\$ .