Suppose that $A$ and $B$ are points on the number line. If $A B=9$ and $B$ lies at -7 , where could $A$ be located? If there is more than one location, separate them with commas.

Step 1 ：Given that B is located at -7 and the distance between A and B is 9, we have two possible scenarios:

Step 2 ：If A is to the left of B, then A = B - AB = -7 - 9 = \(-16\)

Step 3 ：If A is to the right of B, then A = B + AB = -7 + 9 = \(2\)

Step 4 ：\boxed{-16, 2}