Respuesta :

First, we have to factor the number.
[tex]1764=42^2[/tex]
We are left with.
[tex]=\sqrt{42^2}[/tex]
There's a rule that says: [tex]\sqrt[n]{a^n}=a[/tex]
Let's apply it.
[tex]\sqrt{42^2}=42[/tex]
Done!

Have a nice day!  :)