A decrease means it is going into the negative direction on the number line.
This is represented by the integer -11.
I'd say that your answer would be 4/6=2/3 of the job is incomplete.
We can plug those values into the equation, and if the answer is incorrect, we'll know if either one is extraneous.
√11 - 2(-7) = √(-7)^2 + 4(-7) + 4
√25 = √25
5 = 5
The first solution, -7, makes the equation true, and so it is not extraneous.
√11 - 2(1) = √(1)^2 + 4(1) + 4
√9 = √9
3 = 3
The second solution, 1, makes the equation true, and so it is also not extraneous.
<h3>The correct option is D, neither solution is extraneous. </h3>