Answer:
2x - 7
Step-by-step explanation:
Twice a number x means x times 2, which can be written as 2x
Minus 17 from 2x
We want to find a scalar function

such that

.
So we need to have

Integrating both sides with respect to

gives

Differentiating with respect to

gives



So we find that

By the fundamental theorem of calculus, we then know the line integral depends only on the values of

at the endpoints of the path. Therefore
<u>Let's solve this problem step-by-step</u>
<u>Let's set</u>:
2x + 6y = 36 -- equation 1
x + 4y = 20 -- equation 2
(equation 2) * 2
2x + 8y = 40 -- equation 3
(equation 3) - (equation 1)
2y = 4
y = 2 -- equation 4
Plug (equation 4)'s value of y into (equation 2)
x + 4(2) = 20
x = 20 - 8
x = 12
<u>Thus x = 12 and y = 2</u>
<u>Let's check, by substituting these values</u>

<u>Answer: x = 12 and y = 2</u>
Hope that helps!
It is D. ,that one makes the most sense to me