Match the terms with the definitions. 1. The horizontal number line in the coordinate plane. 2. A symbol or letter representing one or more numbers. 3. Two sets A and B (A U B) is the sets consisting of the elements that are in either A or B, or in both of the sets. 4. The set of natural numbers with zero included. The set of whole numbers is written {0, 1, 2, 3, 4, ...}. 5. The second component in an ordered pair used to locate a point on a plane, also called the ordinate. a. Union of sets b. Variable c. Whole numbers d. X-axis e. Y-coordinate
