Respuesta :

18/42 =  3/7

15/40 = 3/8

18/42 simplifies to 3/7, the greatest common number you can divide by is 6 so 18/6 is 3 and 42/6 is 7, so 3/7


15/40 simplifies to 3/8. The greatest number you can divide by is 5. So 15/5 is 3 and 40/5 is 8, making 3/8.