Respuesta :

Answer:

N = 3

Step-by-step explanation:

[tex] \frac{28}{4} = \frac{21}{N} \\ \\ 28N = 21 \times 4 \\ 28N = 84 \\ \\ N = \frac{84}{28} \\ \\ N = 3[/tex]

I hope I helped you^_^