A number and its opposite have the same absolute value and different signs. The first number is equal to 12, and the second is $\displaystyle-{12}\usepackage{cmbright}\Huge\$ . So these are opposites. The correct answer is 36 and $\displaystyle{\left|-{36}\right|}\usepackage{cmbright}\Huge\$ because $\displaystyle{\left|-{36}\right|}={36}\usepackage{cmbright}\Huge\$ , so the numbers are not opposites.