Hey there!
First we have to distribute the negative terms
Like:
[tex]8a + (-1) (4 + a)\\ \\ = 8a+ (-1) *4(-1a) \\ \\ = 8a + (-4) + (-a) [/tex]
Combine like terms
Like:
[tex]8a, -a\\ \\ -4 \\ \\ 8a + (-4) + (-a)\\ \\ = 8a + (-a) + (-4) \\ \\ = 7a + (-4) [/tex]
[tex]Answer: 7a - 4 [/tex]
Good luck on your assignment and enjoy your day!
~[tex]LoveYourselfFirst:)[/tex]