algebra fraction thing!!! pls explain I'm so lost??? like I don't see why the answer isn't 2n-2? did my teacher make a mistake or am I missing something?

Answer:
a.
Step-by-step explanation:
[tex] \frac{n - 9}{2n - 5} + \frac{3n - 1}{2n - 5} [/tex]
Since the denomaitor is the same, just add straight across.
[tex] \frac{4n - 10}{2n - 5} [/tex]
The numerator can be factored.
The greater common factor is 2 so we have
[tex] \frac{2(2n - 5)}{2n - 5} [/tex]
Notice that the numerator and denomiator are the same.
This means they will divide out to 1 so we have
[tex]2[/tex]