To simplify the expression \( (4^{6})(4^{-8}) \), you can use the property of exponents that states \( a^m \cdot a^n = a^{m+n} \).
Applying this property, we get:
\[ (4^{6})(4^{-8}) = 4^{6 + (-8)} = 4^{-2} \]
Now, \( 4^{-2} \) can be rewritten in terms of positive exponents:
\[ 4^{-2} = \frac{1}{4^2} = \frac{1}{16} \]
Therefore, the simplified expression is:
\[ (4^{6})(4^{-8}) = \frac{1}{16} \]