Answer:
[tex]3a-4b-13[/tex]
Step-by-step explanation:
Given: [tex](2a+5b-7)+(a-9b-6)[/tex]
Since we are adding, there is no real use for the parenthesis. This may help you visualize it better.
[tex]2a+5b-7+a-9b-6[/tex]
Combine like terms:
[tex]3a-4b-13[/tex]