Answer:
-287
Step-by-step explanation:
If x + y = z, then z - y = x and z - x = y. Since 260 + x = -27, then -27 - 260 = x.
You can change the signs for a moment but you need to change them back at the end. 27 + 260 = 287, flip the signs, -27 - 260 = -287.
