Question

If a and b are two rational numbers, then a+b is also a rational number. This property is known as

Answer 1

this is known as the closure property .
where
a + b = c
if a,b are rational numbers, c has to be a rational number

Answer 2

$\huge{Hey mate!!}$

here is your answer:

The following property is known as the $\bf\color{Orange}{Closure Property}$ of rational numbers.(under addition)

According to this property rational numbers are closed under addition this means that the sum of two rational numbers will also be a rational number.

hope it helps you!!

$\boxed{Thankyou!!}$