Final answer:
The union of (4,19) and (5,45) is (5,19). The intersection is an empty set.
Step-by-step explanation:
The union of two sets, denoted by U, refers to the set that contains all elements that are in either one of the two sets.
The intersection of two sets, denoted by ∩, refers to the set that contains all elements that are common to both sets.
In this case, the union of (4,19) and (5,45) will include all numbers between 4 and 19, as well as all numbers between 5 and 45, except for the numbers 4 and 45.
Therefore, the union is (5,19).
The intersection of the two sets will only include the numbers that are common to both sets, which in this case is an empty set since there are no numbers that are in both sets.