Exercise 4 Page 218

Since we have the symbol ⋃, we are looking for the union of the given sets. Y&={1, 2, 3, 4, 5, 6, 7, 8, 9, 10} Z&={ 1, 3, 5, 7, 9} A union of two sets is the set that contains all elements found in both sets. Therefore, the union of Y and Z holds all elements that are in both Y and Z. Note that a union only contains unique values, so if any elements exist in both sets, we will cross out the duplicates. Z&={ 1, 3, 5, 7, 9} Y&={1, 2, 3, 4, 5, 6, 7, 8, 9, 10} Y ⋃ Z &={1, 2, 3, 4, 5, 6, 7, 8, 9, 10} We see that Y⋃ Z is the same set as Y, because Y already contains all elements of Z.