Solve the equation x2 + 4x - 7 = 0
by completing the square.
Give your answers correct to 2 decimal places.

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 = ± ( subtract 2 from both sides )

x = - 2 ±

Then

x = - 2 - ≈ - 5.32 ( to 2 dec. places )

x = - 2 + ≈ 1.32 ( to 2 dec. places )