Answer:
x = 2 ± [tex]\sqrt{15}[/tex]
Step-by-step explanation:
x² - 4x - 11 = 0 ( add 11 to both sides )
x² - 4x = 11
to complete the square
add ( half the coefficient of the x- term )² to both sides
x² + 2(- 2)x + 4 = 11 + 4
(x - 2)² = 15 ( take square root of both sides )
x - 2 = ± [tex]\sqrt{15}[/tex] ( add 2 to both sides )
x = 2 ± [tex]\sqrt{15}[/tex]
