Answer: C
Step-by-step explanation: your fast answer is C.
To get better at 12's:
Write down on your paper your 1's facts in column skip 5 and 11 going to 14 (a vertical line - line that goes up and down). To the right of that column, write your two's facts 0 to 8 and repeat again. Then you will have your 12's! Should look as follows
12's:
0 0 = 12 x0
1 2 = 12 x1
2 4 = 12 x2
3 6 = 12 x3
4 8 = 12 x4
6 0 = 12 x5
7 2 = 12 x6
8 4 = 12 x7
9 6 = 12 x8
10 8 = 12 x9
12 0 = 12 x10
13 2 = 12 x 11
14 4 = 12 x 12
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.
I am going to guess C but I’m not entirely sure
