Simplify the Expression $$\left( \frac { 2 x ^ { - 4 } y ^ { 5 } } { 5 x ^ { 4 } y ^ { - 7 } } \right) ^ { - 3 }$$

Short Answer

Simplify the expression. Write your answer with positive exponents only. $$\left( \frac { 2 x ^ { - 4 } y ^ { 5 } } { 5 x ^ { 4 } y ^ { - 7 } } \right) ^ { - 3 }$$