Step-by-step explanation:
[tex] = (s - 6) + (8s + 4)[/tex]
[tex] = s - 6 + 8s + 4[/tex]
Combine the like terms..
[tex] = s + 8s - 6 + 4[/tex]
[tex] = \boxed{\sf{9s - 2}}[/tex]
hence the answer is 9s - 2 .....
hope it helped !!!