We will first solve by substituting the value of x and then plot to emphasise our answer.
[tex]\begin{gathered} 5x-4y=20 \\ x=4 \\ \text{ Substituting this value of x gives:} \\ 5(4)-4y=20 \\ y=\frac{20-20}{-4}=0 \end{gathered}[/tex]
We have our graph below:
