Answer:
The answer is C.
Step-by-step explanation:
Given that (5,k) lies on the line that has the equation of 2x + y = 9. So in order to find k, you have to substitute the coordinates into the equation :
[tex]2x + y = 9[/tex]
Let x = 5,
Let y = k,
[tex]2(5) + k = 9[/tex]
[tex]10 + k = 9[/tex]
[tex]k = 9 - 10[/tex]
[tex]k = - 1[/tex]