In addition, we have proved that even the set of irrationals also is neither open nor closed.
Closure property For two rational numbers say x and y the results of addition, subtraction and multiplication operations give a rational number. We can say that rational numbers are closed under addition, subtraction and multiplication. For example: (7/6)+(2/5) = 47/30.
Closure property of rational numbers under subtraction: The difference between any two rational numbers will always be a rational number, i.e. if a and b are any two rational numbers, a – b will be a rational number.
The closure property states that for any two rational numbers a and b, a + b is also a rational number. The result is a rational number. So we say that rational numbers are closed under addition.
The closure property of addition states that when any two elements of a set are added, their sum will also be present in that set. The closure property formula for addition for a given set S is: ∀ a, b ∈ S ⇒ a + b ∈ S.
Irrational numbers are not closed under addition, subtraction, multiplication, and division.
Lesson Summary OperationNatural numbersIrrational numbers Addition Closed Not closed Subtraction Not closed Not closed Multiplication Closed Not closed Division Not closed Not closed
Some of the examples of rational numbers are 1/2, 1/5, 3/4, and so on. The number “0” is also a rational number, as we can represent it in many forms such as 0/1, 0/2, 0/3, etc.
The closure property of rational numbers states that when any two rational numbers are added, subtracted, or multiplied, the result of all three cases will also be a rational number.
Example:5/9 + 7/9 = 12/9 is a rational number. Closure Property of Subtraction: The sum of two rational numbers is always a rational number. If a/b and c/d are any two rational numbers, then (a/b) – (c/d) = is also a rational number. Example: 7/9 – 5/9 = 2/9 is a rational number.