Simplify x1(y8z7)2x4y1z4\displaystyle \frac{{{x}^{{-{{1}}}}\cdot{\left({y}^{{-{{8}}}}\cdot{z}^{{7}}\right)}^{{2}}}}{{{x}^{{4}}\cdot{y}^{{1}}\cdot{z}^{{-{{4}}}}}}

Write your answer with positive exponents only.