first you just combine like terms for which you would add
[tex]8k + 4k - 3k[/tex]
which is
[tex]9k[/tex]
then you have to add the other terms
[tex]2 + 5[/tex]
which is
[tex]7[/tex]
now you combine both terms and you end up with the solution of
[tex]7 + 9k[/tex]
