Answer:
[tex]\sf \dfrac{1}{16}[/tex]
Step-by-step explanation:
In exponent multiplication, if bases are same, add the powers.
[tex]\sf \boxed{a^m*a^n=a^{m+n}}[/tex]
[tex]\sf \boxed{a^{-m}=\dfrac{1}{a^m}}[/tex]
[tex]\sf 4^6 * 4^{-8}=4^{6+(-8)}\\\\[/tex]
[tex]\sf =4^{-2}\\\\ =\dfrac{1}{4^2}\\\\=\dfrac{1}{16}[/tex]