First simplify the equation and next multiply the 20 with the x^2 and find a number that adds together to give you the middle
A. The term "units" refers to the measurements in the original question or problem. When looking at the question, the units we are measuring are dollars/feet.
B. In this case, the f'(x) means we are looking for the cost (in dollars) to drill the next foot down.
C. Since the cost increases the more feet we drill down, the sign of f'(x) is positive.
Daily failure rate = probability that it will not work on any particular day.
7/2=y/3
21=2y
Y=21/2
Hope this helps!