During the first stage of the division process, when you should have subtracted $\displaystyle{6}{x}-{2}{x}\usepackage{cmbright}\Huge\$ , you may have added $\displaystyle{6}{x}\usepackage{cmbright}\Huge\$ and $\displaystyle{2}{x}\usepackage{cmbright}\Huge\$ . Then during the second stage you made a similar error in subtraction. Make sure that you distribute the minus sign when you get to the steps involving subtraction.