The sets a and b are shown below
a= (0,5,10,15)
b=(-4,-2,0,2,10)
find the union of a and b

The union of the sets is {-4,-2,0,2,5,10,15}.

The intersection of the sets is {0,10}.

Step-by-step explanation:

means the list elements that you see in either set:

{-4,-2,0,2,5,10,15}.

Notice I didn't list any element twice for occurring in both sets.

means the elements that occur in both set or the elements you see in common between the two if you prefer this wording of the definition:

{0,10}.