Answer:
x ≈ - 2.193 , x ≈ 3.193
Step-by-step explanation:
x² - x - 7 = 0 ( add 7 to both sides )
x² - x = 7
to complete the square
add ( half the coefficient of the x- term )² to both sides
x² + 2(- 0.5)x + 0.25 = 7 + 0.25
(x - 0.5)² = 7.25 ( take square root of both sides )
x - 0.5 = ± [tex]\sqrt{7.25}[/tex] ≈ ± 2.693 ( add 0.5 to both sides )
x = 0.5 ± 2.693
then
x = 0.5 - 2.693 = - 2.193
x = 0.5 + 2.693 = 3.193
