17. 2a- Real numbers can be classified as either rational numbers or irrational numbers, A rational number, like g , is a ratio of two integers. An irrational number, like it or V cannot be written as a ratio of integers. Rational numbers include natural numbers (1, 2, 3,. . . ), whole numbers (0, 1, 2, 3, . . . ), and integers (. .. , -2, -1, 0, 1, 2,... Name the set(s) of numbers to which each number belongs. 21. -3.21 22. V7 23. -2 24. 18 25. 5