Given that a is the smallest positive integer, B is the opposite of a, and the absolute value of C is 3, find a + B+ Value of

Given that a is the smallest positive integer, B is the opposite of a, and the absolute value of C is 3, find a + B+ Value of

Because a = 1, B = - 1, | C | = 3, that is, C = + 3 or - 3,
So a + B + C = 1 + (- 1) + 3 = 3
Or 1 + (- 1) - 3 = - 3

Fill in - 6, - 5, - 4, - 1,0,1,4,5,6 in 3 times 3.9 squares respectively, so that the sum of three numbers in each row, column and diagonal is equal
 
 
 

Let me give you an idea
If 1 - 9 makes the sum of the three numbers of each row, column and diagonal equal, there is only a magic square of order 3
6 1 8
7 5 3
2 9 4
Change 1,2,3 into - 6, - 5, - 4
Change 4,5,6 into - 1,0,1
Change 7,8,9 into 4,5,6
Here comes the case