You may have incorrectly combined the like terms on the left side to get $\displaystyle-{4}{y}\usepackage{cmbright}\Huge\$ . The correct way to combine them is: $\displaystyle{2}{y}-{3}{y}+{5}{y}={\left({2}-{3}+{5}\right)}{y}={4}{y}\usepackage{cmbright}\Huge\$ . Apply the same rules you learned to add and subtract positive and negative numbers. The correct answer is $\displaystyle{y}={8}\usepackage{cmbright}\Huge\$ .