ANSWER
8 units.
EXPLANATION
The first point, A is located at (-9,2) on the coordinate plane.
The second point, B is also located at (-9,10) on the coordinate plane.
You should be smart and observe that the x-coordinates of both points are the same. This means that, the two points lies on a vertical line.
Hence it will be faster to use the absolute value method rather than the distance formula.
According to this method, you only have to find the absolute value of the difference in the y-values.
8 units.
EXPLANATION
The first point, A is located at (-9,2) on the coordinate plane.
The second point, B is also located at (-9,10) on the coordinate plane.
You should be smart and observe that the x-coordinates of both points are the same. This means that, the two points lies on a vertical line.
Hence it will be faster to use the absolute value method rather than the distance formula.
According to this method, you only have to find the absolute value of the difference in the y-values.