You have the following function:

Derivate implictly the previous expression, as follow:

Where you have used that:

Then, the implicit derivative of the given expression is:

Next, solve for y' as follow:

Answer:
54 Minutes
Step-by-step explanation:
45 minutes/5 walls/4 people=2.25 minutes per person per wall
2.25 times 6 times 4=54 minutes
Answer: let me check
Step-by-step explanation:
The answer appears to be 3.335%