Respuesta :

Answer:

C

Step-by-step explanation:

We want to simplify the expression:

[tex]\displaystyle 3 \sqrt{-28}[/tex]

Rewrite:

[tex]\displaystyle = 3 \sqrt{ 4\cdot 7 \cdot -1}[/tex]

Rewrite:

[tex]\displaystyle = 3 \cdot \sqrt{4} \cdot \sqrt{7} \cdot \sqrt{-1}[/tex]

Simplify. Let i = √(-1). Hence:

[tex]\displaystyle = 3 \cdot \left(2\right) \cdot \left(i\right) \cdot \sqrt{7}[/tex]

Multiply:

[tex]\displaystyle = 6i\sqrt{7}[/tex]

In conclusion, our answer is C.