Use Properties of Exponents to Simplify $$\left( 9 ^ { 1 + \sqrt { 7 } } \right) \left( 9 ^ { 1 - \sqrt { 7 } } \right)$$

Multiple Choice

Use properties of exponents to simplify. $$\left( 9 ^ { 1 + \sqrt { 7 } } \right) \left( 9 ^ { 1 - \sqrt { 7 } } \right)$$

A) 49
B) 81
C) 16
D) $9 \sqrt { 7 }$
E) 343