Step-by-step explanation:
[tex] = ( - 4s + 9) + (4s - 6)[/tex]
[tex] = - 4s + 9 + 4s - 6[/tex]
[tex] = - 4s + 4s +9 - 6[/tex]
Now subtract.....
[tex] = \boxed{\sf{3}}[/tex]
hence the answer is 3 ....
hope it helped !!!!