Solving this equation, we have:
[tex]\begin{gathered} |4x-4\mleft(x+1\mright)|=4 \\ |4x-4x-4|=4 \\ |-4|=4 \\ 4=4 \end{gathered}[/tex]
Since the final sentence is always true, the solution set is all real numbers.
Showing it in the number line in blue, we have:
