Answer:
D
Step-by-step explanation:
Given
2x² + 16x - 8 = 0 ( divide through by 2 )
x² + 8x - 4 = 0 ( add 4 to both sides )
x² + 8x = 4
To complete the square
add ( half the coefficient of the x- term )² to both sides
x² + 2(4)x + 16 = 4 + 16
(x + 4)² = 20 ( take the square root of both sides )
x + 4 = ± [tex]\sqrt{20}[/tex] = ± [tex]\sqrt{4(5)}[/tex] = ± 2[tex]\sqrt{5}[/tex] ( subtract 4 from both sides )
x = - 4 ± 2[tex]\sqrt{5}[/tex] → D
