Respuesta :

Answer:

[tex]N=2 \sqrt{7} i[/tex]

Step-by-step explanation:

Imaginary or complex numbers

The complex numbers are identified from real numbers because they have an imaginary part, the unit [tex]i=\sqrt{-1}[/tex]

Our number is  

[tex]N=\sqrt{-28}[/tex]

which can be expressed as

[tex]N=\sqrt{(-1)(4)(7)}[/tex]

[tex]N=\sqrt{-1} \sqrt{4} \sqrt{7}[/tex]  

[tex]N=i (2) \sqrt{7}[/tex]

[tex]N=2 \sqrt{7} i[/tex]