Cancel out the denominators.
(x+5)² + 18 = -30
(x+5)² = -30 - 18
(x+5)² = -48
The equation is impossible, we have a negative number.
There isn't a number that squared gives a negative number (the square is always positive).
√(x+5)² = +/- √-48
x+5 = +/- √-48
IMPOSSIBLE
You can write the result in imaginary numbers
x+5=+/- 4i√3