If A-B = B-A and a = 4, B = 3, find the value of a + B

If A-B = B-A and a = 4, B = 3, find the value of a + B

∵ A-B = B-A
∴b-a>=0
b>=a
∵|a|=4
A = 4 or - 4
∵|b|=3
| B = 3 or - 3
∵b>=a
∴b=3 a=-4
b=-3 a=-4
A + B = - 1 or - 7