Add 5 to both sides of the equation: $\displaystyle-{2}{\left|{b}-{3}\right|}={12}\usepackage{cmbright}\Huge\$

Divide both sides of the equation by $\displaystyle-{2}\usepackage{cmbright}\Huge\$ : $\displaystyle{\left|{b}-{3}\right|}=-{6}\usepackage{cmbright}\Huge\$

Since it's impossible to have an absolute value equal to a negative number, this equation has no solution.