To solve this problem you must apply the proccedure shown below:
1- You have the following expression given in the problem above 2^4x2^-7
2- You can find and equivalent expression as following: The negative exponent indicates that 2^7 must be in the denominator:
=2^4/2^7
3- By simplifying, you obtain:
=1/2^3
=1/8
Therefore, the answer is: 1/8