Which expression is equivalent to 2^4 x 2^-7?

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

1.17+3.99a. you combine the terms with a to create 3.99 and the 1.17 stays because it has no like terms or a variable