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.
Conclusion. It is evident that rational numbers can be expressed both in fraction form and decimals. An irrational number, on the other hand, can only be expressed in decimals and not in a fraction form. Moreover, all the integers are rational numbers, but all the non-integers are not irrational numbers.
Irrational numbers are not closed under addition, subtraction, multiplication, and division.
Answer: The closure property says that for any two rational numbers x and y, x – y is also a rational number. Thus, a result is a rational number. Consequently, the rational numbers are closed under subtraction.
The set of rational numbers are determined to be neither an open set nor a closed set. The set of rational numbers is not considered open since each neighborhood of the numbers in the set holds an irrational number.
Lesson Summary OperationNatural numbersIrrational numbers Addition Closed Not closed Subtraction Not closed Not closed Multiplication Closed Not closed Division Not closed Not closed
Closure Property: This tells us that the result of the division of two Whole Numbers might differ. For example, 14 ÷ 7 = 2 (whole number) but 7 ÷ 14 = ½ (not a whole number).
Let us say that we have three numbers, 'a,' 'b,' and 'c,' for addition, the associative law for Rational Numbers states that: a + (b + c) = (a + b) + c, and for multiplication, the associative law for Rational Numbers states that: a(bc) = (ab)c.
Answer: So, adding two rationals is the same as adding two such fractions, which will result in another fraction of this same form since integers are closed under addition and multiplication. Thus, adding two rational numbers produces another rational number. Rationals are closed under addition (subtraction).