There is an ambiguity here so I’ll give two solutions, depending on what the question means.
First, let’s assume it’s -6+¼x=-5. Add 6 to each side: ¼x=1, so x=4.
Now let’s assume it’s (-6+x)/4=-5. Multiply both sides by 4:
-6+x=-20, add 6 to each side: x=-14.