You can put this solution on YOUR website! Sorry about my mistake in handeling these exponents.
They should have been multiplied instead of added.
(x^-7y^11z^14)^-2
x^(-7*-2)=x^14
y^(11*-2)=y^-22
z^(14*-2)=z^-28
When you are raising powers to another power you multiply the exponents.
x^14y^-22z^-28
Negative exponents are changed to positive exponents by taking the reciprical of the term.
x^14/y^22z^28 ans.