After substitution you will have $\displaystyle{\left({3}\cdot{\left(-\frac{{1}}{{5}}\right)}\right)}\cdot{5}\usepackage{cmbright}\Huge\$ . Applying the associative property would regroup the factors as $\displaystyle{3}\cdot{\left({\left(-\frac{{1}}{{5}}\right)}\cdot{5}\right)}\usepackage{cmbright}\Huge\$ . In this answer, the negative has been grouped with the 3.