Hi Theresa;
√81x^{6}
If I understand correctly, the whole thing is being squarerooted.
square root of 81=9
square root of x^{3}=x^{6}
The latter is because (x^{3})(x^{3})=(x^{6})3+3=6
You wanted factoring...
Assuming that it is all being square rooted, let's factor.
√81x^{6}
√(9x^{3}+0)(9x^{3}+0)=(9x^{3}+0)=9x^{3}
Is this what you wanted? Please let me know either way.
10/12/2013

Vivian L.