[tex] \sqrt{864} [/tex]
[tex] \sqrt{4 \times 216} [/tex]
[tex] \sqrt{4 \times 4 \times 54} [/tex]
[tex] \sqrt{4 \times 4 \times 2 \times 27} [/tex]
[tex] \sqrt{4 \times 4 \times 2 \times 9 \times 3} [/tex]
now take out the pairs.
[tex]4 \sqrt{2 \times 9 \times 3} [/tex]
take out any of the square roots like 9
[tex]4 \times 3 \sqrt{2 \times 3} [/tex]
Now put it all back together.
[tex]12 \sqrt{6} [/tex]
I believe that is the answer.
