Respuesta :

Answer:

7

Step-by-step explanation:

5/15=1/3

21÷3=7

1×7=7

3×7=21

n=7

Answer:

7

Step-by-step explanation:

5÷5=1

15÷5=3

thus,

5/15=1/3

1/3=n/21

n=?

21÷3=7

n=7