Answer:

Step-by-step explanation:
when adding logs, apply the log rule: 
∴ 
when subtracting logs, apply the log rule: 

Given the first was Windows, we're choosing the second from 17 macs and 12 Windows, so

Answer:
the answer is B) 12a+6b
Step-by-step explanation:
3+9=12 so 3a+9a=12a,
7-1=6 so 7b-(1)b=6b
Answer:
Step-by-step explanation:
Can you answer the question in blue please