¿Cuáles son las propiedades de la suma de números racionales

Step-by-step explanation:

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. Commutative property of addition of rational numbers: Two rational numbers can be added in any order.

Fraction means  a part of something

we see
18 times a fraction is bigger or smaller or equal to 18

18 times a fraction means take a part ouf of 18
in this case
18 times 4/5=72/5=14.4
14.4 is less than 18
when  you take a fraction of something, it becomes smaller, like if you take a slice of pizza or a fraction of the pizza, it becomes smaller

lesss