I’m only needing A everything else is good

It would be 9 units.

Step-by-step explanation:

So to find the distance between two points, first start at one of the points then see how much distance there is between it and 0.

So taking 7 to start with, you would need to walk 7 units to get to 0.

However, we still need to get the distance till -2. So, we need to walk another 2 steps back, so it would be 9 units of walking in total.