When simplified, -x − x is:

-2x

Explanation:
Lets put 1s in front of these x’s so that it is easier to explain.
-1x-1x
This is the same as -1-1, which gives you negative 2.
Now, put an x in front of that -2!
-2x. Boom, there’s your answer.

Hope this helps! mark brainliest if you can please :$

I'll say power property,final answer