A rule of thumb in these type of equations (at least, for me, personally) is to bracket off the like term. We’ve got 3 things here, so we gotta bracket them.
(5)+(10s-8s)
So now, we’ve got them separated. Next, we perform our given function. In this case, we subtract 8 from 10, leaving us with 2.
(5)+(2s)
As we no longer have any like terms, to be simplified or otherwise, we open the brackets:
5+2s
And you’ve obtained your answer!
Answer= 5+2s