Question

Solve x2 + 8x – 3 = 0 using the completing-the-square method.

Answer 1

$x = -4 \pm \sqrt{19}$

Step-by-step explanation:

Let us put 3 on the right side and rewrite the equation as

$x^2 + 8x = 3$

By putting 16 on both sides, our equation becomes

$x^2 + 8x + 16 = 3 + 16 = 19$

$\Rightarrow (x + 4)^2 = 19$

Taking the square root of the equation, we get

$x + 4 = \pm \sqrt{19}$

Finally, solving for x,

$x = -4 \pm \sqrt{19}$