Answer
−1 + i times the square root of 7
Explanation
x² + 2x + 8
I will use the complete square method to find the value of x.
x² + 2x + 8
x² + 2x = -8
x² + 2x + (2/2)² = -8 + (2/2)²
x² + 2x + 1 = -7
(x + 1)² = -7
x + 1 = √(-7)
x = √(-7) - 1
= i√7 - 1
= -1 + i√7
−1 + i times the square root of 7
