Solve x 2 + 8x + 8 = 0 by completing the square.
Mathematics · High School · Mon Jan 18 2021
llm
Answered on
We have,
x² + 8x + 8 = 0
Adding 8 to both side, we get
x² + 8x + 8 + 8 = 0 + 8
x² + 8x + 16 = 8
(x + 4)² = 8
By (a+b)² = a² + 2ab + b²
Now, taking square root of both sides, we get
(x + 4) =± √8
x = ± 2√2 -4
Taking positive sign
x = 2√2 - 4
x = 2( √2 - 2)
Now, taking negative sign,
x = -2 √2 - 4
x = -2( √2 + 2)