It appears that you correctly applied the division process up until the last step. At that point you should have subtracted $\displaystyle-{2}{{x}}^{{2}}-{3}{x}-{4}-{\left(-{2}{{x}}^{{2}}-{8}{x}-{6}\right)}\usepackage{cmbright}\Huge\$ . You may have added the terms $\displaystyle-{8}{x}-{6}\usepackage{cmbright}\Huge\$ to $\displaystyle-{3}{x}-{4}\usepackage{cmbright}\Huge\$ . Make sure that you distribute the minus sign when you get to the steps involving subtraction.