Simplify or otherwise reduce: 2^4 X 2^5 / 2^7 - 2/4

[JoeK882]

This is from MGMAT Number Properties guide chapter 5 Exponents page 71:

Simplify or otherwise reduce: 2^4 X 2^5 / 2^7 - 2/4

In the answer key I can see the answer is -12 as well as the steps, but I need a further explanation.

Thanks!

[RonPurewal]

Hello,

- Please re-post this question in the MGMAT non-CAT math folder.

- When you re-post the question, please include some comments on your own existing thought process.
(What did you understand? What didn't you understand? At what point in the process did you get stuck? Etc.)

Thank you.