I need to write an interval notion for

Question

9<x<14 = how do I write this?

Answer 1

(9,14)

Answer 2

I thought I needed Brackets or such

Answer 3

Brackets are used for included endpoints.

(9,14) for 9 < x < 14
[9,14) for 9 <= x < 14
(9,14] for 9 < x <= 14
[9,14] for 9 <= x <= 14