The given inequality is
![x-y>8](https://img.qammunity.org/2023/formulas/mathematics/high-school/oqs6j9wqjd6gsb68k8w0j2bece05sm1htr.png)
The given coordinates are (7,4), (3.8, 4) and (0,9).
Let's evaluate each coordinated pair in the inequality to see which one satisfies it.
For (7,4).
![\begin{gathered} 7-4>8 \\ 3>8 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/high-school/mtp5kxqdd96rqlllsi3pomutmxgm9sifm0.png)
Since 3 is not more than 8, we say (7,4) is not a solution.
For (3.8, 4).
![\begin{gathered} 3.8-4>8 \\ -0.2>8 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/high-school/eehdvsjpxxlqvdghc178arhtt6muvxhnim.png)
Since -0.2 is not more than 8, we say (3.8, 4) is not a solution.
For (0,9).
![\begin{gathered} 0-9>8 \\ -9>8 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/high-school/2j3gjsieiqsvcosf0ssx5rpiop38ucirbp.png)
Since -9 is not more than 8, we say (0,9) is not a solution.
Therefore, neither given point is a solution of the given inequality.