Final answer:
The union of intervals involves combining overlapping or adjacent intervals into one larger interval, requiring sorting the intervals and merging where applicable.
Step-by-step explanation:
The union of intervals is a process in mathematics where two or more intervals are combined into a single set that includes all the values from each interval.
When performing the union of intervals that are given in list format, such as -2 or any of the sets listed, it typically involves identifying overlapping and adjacent intervals and joining them together to form a larger interval when applicable.
To do a union of intervals, you would need to sort the intervals first. For example, if the intervals are (-9, -2), (-7, -1), (-22, -18), and (-44, -20), you would first arrange them in order by the starting number: (-44, -20), (-22, -18), (-9, -2), (-7, -1). Next, you would check for overlaps or adjacent intervals and merge them.
In this case, the intervals (-22, -18) and (-44, -20) overlap, so they can be merged into one interval: (-44, -18). The final union of these intervals would be (-44, -1), combining all the intervals into a single set.