The given Expression is :

From the property of exponents
If the base value of the exponents are same then during the process of multiplication powers will add up.
Since in the given expression 4 is the base value on both base of the exponents
Thus, base value are equal
The powers will add up:

Simplify the farction of the exponents :

So, the value of the given expression will be :

Answer : 4 ^8/15