Simplify $\left( 2 x ^ { 9 } y ^ { - 8 } \right) \left( 4 x ^ { - 12 } y ^ { 9 } \right)$

Short Answer

Simplify. $\left( 2 x ^ { 9 } y ^ { - 8 } \right) \left( 4 x ^ { - 12 } y ^ { 9 } \right)$ Your answer should include only positive exponents.