Hi there!
To solve for your equation, first, it would be a little helpful to rewrite it, as it looks easier to work out.

Let us begin!
Step 1) Simplify both sides of the equation. (Below are the steps on how to simplify!)

Pretty simple to simplify! :D
Step 2) Add 6 to both sides.

Pretty easy so far!
Step 3) Divide both sides by -2.

Final Answer -

See, it wasn't so bad! If anything, it was too easy! :)
Hope this helps! :D
Message me if you need anymore help with anything!