Answer
? = -91
Step-by-step explanation:
Let's keep the question mark as x
x must be a negative number if there is a subtraction sign before it, if the first number of the problem is negative, and the difference is positive.
-28 - (-x) = 63
-28 -1(x) = 63
-1(x) = 63 +28 = 91
/-1 /-1
x = -91
? = -91
