We start by substituting the value of 3x for y in the first equation
We have this as;
[tex]\begin{gathered} 4x-2(3x)\text{ = -4} \\ 4x\text{ - 6x = -4} \\ -2x=\text{ -4} \\ x\text{ = }\frac{-4}{-2} \\ x\text{ =2} \\ \text{From i}i\colon\text{ y = 3x ; y = 3(2) ; y = 6} \end{gathered}[/tex]