While using the distributive property to clear the parentheses, you forgot that a negative number times a negative number is positive. So $\displaystyle-{3}{\left({3}{h}-{2}\right)}\usepackage{cmbright}\Huge\$ becomes $\displaystyle-{9}{h}+{6}\usepackage{cmbright}\Huge\$ , not $\displaystyle-{9}{h}-{6}\usepackage{cmbright}\Huge\$ .