Answer:
4:9 or 4/9 depending on how your teacher or computer program wants it entered. Some use the colon (:) some use the slash (/).
Step-by-step explanation:
1. Betta fish = 12
2. Total fish = 27 (15 neon + 12 betta)
3. 12:27 or can be writte as 12/27 depending on your teacher or computer program.
4. Can be simplified by dividing by 3
12/3 and 27/3
5. 4:9 or 4/9