Q1. If A = {x | x is an odd integer}, B = {x | x is an even integer}, C = {2, 3, 4, 5}, and D = {18, 19, 20, 21}, list the element(s) of the set C ∪ D.

Background

Topic: Set Theory – Union of Sets

This question is testing your understanding of the union operation in set theory, which is a foundational concept in intermediate algebra. The union of two sets includes all elements that are in either set or in both sets.

Key Terms and Formulas

• Union ( ∪ ): The union of sets A and B, written as A ∪ B, is the set of all elements that are in A, in B, or in both.

• Set notation: Curly braces { } are used to list elements of a set.

Step-by-Step Guidance

1. Start by listing all the elements in set C. According to the question, .

2. Next, list all the elements in set D. According to the question, .

3. Recall the definition of union: is the set of all elements that are in C, in D, or in both.

4. Combine the elements from both sets, making sure not to repeat any elements. Write out the union set using set notation.

Try solving on your own before revealing the answer!