It would take one person twice the time so a) 12 hours
12/3 is 4 so b) 4 hours
Hi,
Solving:

Answer: The statement is true for any value of x.
Hope this helps.
r3t40
The answer is 
*Remember x=
You are technically dividing in this, whenever you divide anything with exponents, you subtract them. 
Therefore, the x's would cancel out, leaving just 
Answer:a
Step-by-step explanation:
Answer: Try D
Step-by-step explanation: