Respuesta :

rational numbers can be written as a ratio of two integers a/b

1/2 is the ratio of 1 and 2 so its rational

√7/10 is not a ratio of two integers so its irrational

3π/4 is not a ratio of two integers so its irrational

5/9  is the ratio of 5 and 9 so its rational

18 is 18/1 and is the ratio of 18 and 1 so its rational