We need to isolate n.
-52 - n = 25
Add 52 to both sides.
-n = 77
Divide both sides by -1.
n = -77
To check if this is right, plug it in.
-52 - (-77) = 25
Flip the sign because to addition because it is a double negative.
-52 + 77 = 25
Simplify.
25 = 25
It is true, so n = -77.