
Expanding the left side gives

which gives two solutions,

and

. But if

, then

, but this number isn't real, so

is an extraneous solution. Meanwhile if

, you get

, so this solution is correct.
"Potential solutions" might refer to both possibilities, but there is only one actual (real) solution.
Answer:
I don't know what you're answer is supposed to look like but if you're creating an equation it should be this...
Step-by-step explanation:
( 4 · √x ) - ( 8 · √x )
Horizontal distance = 48'
difference in elevation = 18"-6" = 12" = 1'
Slope of the sewer line = rise/run = 1/48 = 0.0208 = 2.08%
Your answer ---> D . 2 2/9