Answer:
x ≈ - 5.32, x ≈ 1.32
Step-by-step explanation:
Given
x² + 4x - 7 = 0 ( add 7 to both sides )
x² + 4x = 7
To complete the square
add ( half the coefficient of the x- term )² to both sides
x² + 2(2)x + 4 = 7 + 4
(x + 2)² = 11 ( take the square root of both sides )
x + 2 = ± [tex]\sqrt{11}[/tex] ( subtract 2 from both sides )
x = - 2 ± [tex]\sqrt{11}[/tex]
Thus
x = - 2 - [tex]\sqrt{11}[/tex] ≈ - 5.32 ( to 2 dec. places )
x = - 2 + [tex]\sqrt{11}[/tex] ≈ 1.32 ( to 2 dec. places )
