Question

Solve x2 + 4x − 4 = 0

Answer Choices:
x = -2 ± √16 all over 2
x = -4 ± √2
x = -2 ± 2 √2
x = 4 ± √18 all over 2

Answer 1

The answer is the third choice

Answer 2

third option

Explanation:

Given

x² + 4x - 4 = 0 ( add 4 to both sides )

x² + 4x = 4

Using the method of completing the square

add ( half the coefficient of the x- term )² to both sides

x² + 2(2)x + 4 = 4 + 4, that is

(x + 2)² = 8 ( take the square root of both sides )

x + 2 = ±
`√(8)` = ± 2
`√(2)` ( subtract 2 from both sides )

x = - 2 ± 2
`√(2)`