Substituting (2, 3) into $\displaystyle{6}{x}+{3}{y}>{15}\usepackage{cmbright}\Huge\$ , you get $\displaystyle{6}{\left({2}\right)}+{3}{\left({3}\right)}>{15}\usepackage{cmbright}\Huge\$ , or $\displaystyle{12}+{9}>{15}\usepackage{cmbright}\Huge\$ . This is a true statement, so (2, 3) is a solution to the inequality.