[tex]3 \sqrt{729} [/tex]
The square root of 729 is in fact 27, as it is a perfect square, but this is not well known, so we can figure it out like this:
What goes into 729 that are perfect squares? 81 and 9:
[tex]3 \sqrt{81*9} [/tex]
Take the square root of 81 (9) and the square root of 9 (3). Move these to the outside of the square root (they will multiply with 3 since 3 is multiplied to the square root in the original problem)
[tex]3 \sqrt{81*9} \\ 3*9*3[/tex]
Now, just multiply:
[tex]3*9*3=81[/tex]
