Solution:
Given:
[tex]y=\frac{2}{3}x-4[/tex]
From the equation given,
[tex]\begin{gathered} x\text{ is the input} \\ y\text{ is the output} \end{gathered}[/tex]
When the input is 18,
[tex]\begin{gathered} x=18 \\ \\ y=\frac{2}{3}x-4 \\ y=\frac{2}{3}(18)-4 \\ y=12-4 \\ y=8 \end{gathered}[/tex]
Therefore, the output is 8.
