You may have correctly canceled common factors and used the quotient rule to simplify this expression to $\displaystyle-{5}\cdot{{w}}^{{-{{2}}}}\usepackage{cmbright}\Huge\$ , but then mistakenly replaced $\displaystyle{{w}}^{{-{{2}}}}\usepackage{cmbright}\Huge\$ with $\displaystyle-{{w}}^{{2}}\usepackage{cmbright}\Huge\$ . A negative exponent does not give you a negative sign. You can rewrite $\displaystyle{{w}}^{{-{{2}}}}\usepackage{cmbright}\Huge\$ as a fraction with a positive exponent. The correct answer is $\displaystyle\frac{{-{5}}}{{{w}}^{{2}}}\usepackage{cmbright}\Huge\$ .