Answer: 16 units
Step-by-step explanation: In this problem, the given numbers -9 and 7 represent the coordinates of the endpoints of a segment and we are asked to find the length of the segment.
To find the length of a segment, we take the greater endpoint coordinate minus the lesser endpoint coordinate.
In this case, the greater endpoint coordinate is 7 and the lesser endpoint coordinate is -9.
So, we have 7 - (-9) which can also be thought of as 7 + 9 which equals 16.
Therefore, the length of this segment is 16 units.
