Proofs are used to confirm or disprove mathematical statements
The missing expression in the proof is : 
<h3>How to complete the proof</h3>
From the question, the first two steps are:


By the properties of exponents, we have:

The above expression represents the missing expression in the proof of the logarithmic expression
Hence, the missing expression is : 
Read more about mathematical proofs at:
brainly.com/question/14036678
8 and 1/2 yeah this is the answer