You may have correctly simplified the inequality to $\displaystyle{\left|{m}+{7}\right|}<{13}\usepackage{cmbright}\Huge\$ , but then only found the solution to $\displaystyle{m}+{7}<{13}\usepackage{cmbright}\Huge\$ . You need to find the solution to the compound inequality $\displaystyle-{13}<{m}+{7}<{13}\usepackage{cmbright}\Huge\$ .