Answer:
All real numbers 
Explanation:
First, distribute the -4 on the left side 
2x-4(x+2)=-2x-8 
2x-4*x+-4*2=-2x-8
2x-4x-8= -2x-8 
Combine like terms on the left side 
-2x -8 = -2x -8 
Since the two sides are equal, all real numbers are solutions 
Hope this helps! :)