ANSWER
D. (-2,5)
EXPLANATION
The given equations are
[tex]8x + 5y = 9...(1)[/tex]
and
[tex]y = x + 7...(2)[/tex]
We substitute equation (2) into equation (1) to get,
[tex]8x + 5(x + 7) = 9[/tex]
We expand the bracket to get,
[tex]8x + 5x + 35 = 9[/tex]
Grouping similar terms, we obtain,
[tex]8x + 5x = 9 - 35[/tex]
Simplify to get,
[tex]13x = - 26[/tex]
Divide both sides by 13 to obtain,
[tex]x = - \frac{26}{13} [/tex]
[tex]x = - 2[/tex]
This implies that,
[tex]y = - 2 + 7[/tex]
[tex]y = 5[/tex]
The solution is (-2,5)
