Substitute $\displaystyle{3}{x}+{2}\usepackage{cmbright}\Huge\$ for y in the second equation: $\displaystyle{4}{\left({3}{x}+{2}\right)}-{12}{x}={8}\usepackage{cmbright}\Huge\$

Simplify: $\displaystyle{12}{x}+{8}-{12}{x}={8}\usepackage{cmbright}\Huge\$ or $\displaystyle{8}={8}\usepackage{cmbright}\Huge\$

This equation is true no matter what value x is, which means that every value of x will give you a solution. So there are an infinite number of solutions.