4^-8 = 1/(4^8)
(4^6) x (1/4^8) = (4^6)/(4^8)
Simplify. Note that when dividing with powers, subtract the powers (if the base is the same number)
(4^6)/(4^8) = 4^(6 - 8)
4^(6 - 8) = 4^(-2)
4^(-2) = 1/(4^2)
1/(4²) = 1/16
1/16 is your answer
hope this helps