Hello, thank you for taking the time to post your question!
Your starting point here is
-8 = -(x + 4)
I would start by dividing both sides by -1
8 = x + 4
Then you can subtract the “4” from both sides to get
x = 8 – 4 = 4
I hope that helps get you moving in the right direction! Feel free to reach out if you have any additional questions beyond that :)