Answer:
x = 4 ± [tex]\sqrt{11}[/tex]
Step-by-step explanation:
To complete the square
add (half the coefficient of the x- term)² to both sides
x² + 2(- 4)x + 16 + 5 = 16
(x - 4)² + 5 = 16 ( subtract 5 from both sides )
(x - 4)² = 11 ( take the square root of both sides )
x - 4 = ± [tex]\sqrt{11}[/tex] ( add 4 to both sides )
x = 4 ± [tex]\sqrt{11}[/tex] ← exact values