Question

Real numbers are ________ under addition. Integers are______ under division. Irrational numbers are _______ under multiplication. Rational numbers are ______ under subtraction.
Options:

closed

or 

not closed

Answer 1

Real numbers are closee under addition.

Explanation: that means that the addtion of two real numbers is always a real number.


Integers are not closed under division.

Explanaton: that means that when  you dived an integer number by another integer number the result may be a non integer number.


Irrational numbers are not closed under multiplication.

Explanation: that means that the multiplication of two irrational numbers may result in a rational number.

Rational numbers are closed  under subtraction.

Explanation: that means that the result of the subtraction of rational numbers is always a rational number.