Answer:
Yes, rational numbers are closed under addition.
Explanation:
Rational numbers are number that can be expressed in the form of fraction
, where x and y are integers and y ≠ 0.
Now, the closure property of addition of rational number states that if we add two rational number, then the sum of these two rational number will also be a rational number.
Let a and b be two rational number, then,
a+b = c, where c is the sum of and b
c is also a rational number.
Thus, rational numbers are closed under addition.
This can be explained with the help of a example.
=

It is clear that
are rational numers.
Thus, rational numbers are closed under addition.