$\displaystyle{9}{\left({3}{y}-{2}\right)}={9}{\left({3}{y}\right)}-{9}{\left({2}\right)}={27}{y}-{18}\usepackage{cmbright}\Huge\$ . Substitute 2 for $\displaystyle{y}\usepackage{cmbright}\Huge\$ :
$\displaystyle{27}{\left({2}\right)}-{18}={54}-{18}={36}\usepackage{cmbright}\Huge\$