Hello!
Let's solve by distributing.
[tex]13(b + 1) - 6 - 3b - 5
13b + 13 - 6 - 3b - 5[/tex]
Now we add/subtract like terms.
[tex]13b + 13 - 6 - 3b - 5
13b + 7 - 3b - 5
13b + 2 - 3b
10b + 2[/tex]
Your final equation is [tex]10b + 2[/tex], which cannot be simplified further, making it our final answer.
Hope I helped! :3