We have to solve:
[tex]\begin{gathered} 3x+2y=16 \\ y=-4 \end{gathered}[/tex]We already know the value of y (y=-4).
We replace the value of y in the first equation and solve for x:
[tex]\begin{gathered} 3x+2(-4)=16 \\ 3x-8=16 \\ 3x=16+8 \\ 3x=24 \\ x=\frac{24}{3} \\ x=8 \end{gathered}[/tex]The value of the pair is (8,-4).
