Since $\displaystyle{x}=-{3}\usepackage{cmbright}\Huge\$ , the polynomial equals $\displaystyle-{{\left(-{3}\right)}}^{{3}}+{5}{{\left(-{3}\right)}}^{{2}}-{7}=-{\left(-{27}\right)}+{5}{\left({9}\right)}-{7}={27}+{45}-{7}={65}\usepackage{cmbright}\Huge\$ .