Answer: 58 units
Step-by-step explanation: In this problem, the given numbers 19 and -39 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 19 and the lesser endpoint coordinate is -39.
So, we have 19 - (-39) which can also be thought of as 19 + 39 which equals 58.
Therefore, the length of this segment is 58 units.