Correct. Distributing the negative sign outside the second parentheses to all the terms inside gives you $\displaystyle{102}{{x}}^{{2}}{y}-{5}{{x}}^{{2}}-{21}{{x}}^{{2}}{y}+{8}{{x}}^{{2}}+{3}{y}+{16}\usepackage{cmbright}\Huge\$ . Simplifying this equation yields $\displaystyle{81}{{x}}^{{2}}{y}+{3}{{x}}^{{2}}+{3}{y}+{16}\usepackage{cmbright}\Huge\$ .