Respuesta :

Answer:

3/5, 17/21, 9/5

Step-by-step explanation:

2/5 + 3/15 = 2/5 + 1/5 = 3/5

2/3 + 1/7 = 14/21 + 3/21 = 17/21

12/5 - 3/5 = 9/5