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.
Answer: x=-2 and y=-2
Step-by-step-explaination:
To solve the system of equations you have to cancel out a variable. I chose to cancel out Y. First, the coefficients of y need to be the same in both equations. To do this multiply to the top equation by 2 so you get
2(2x) +2(y) = 2(-6)
4x + 2y = -12
Next, subtract the second equation from the first to cancel out the y’s
4x + 2y =-12
-(-8x + 2y = -12)
————————
12x = -24
Solve
X = -24/12
X=-2
Plug x into the original equation to find y
2(-2) + y = -6
-4 + y = -6
Y = -6 +4
Y=-2
You can substitute x and y into the original equations to double check
Answer:
D
Step-by-step explanation:
= 
Factor out 2 on the numerator and 2x on the denominator.
= 
Cancel the factor (x + 2) on the numerator/ denominator
= 
← cancel the 2 on numerator/ denominator
= 
: x ≠ 0
1. (54/9)6 equation
6 x 6
36 answer
