Solve the equation by completing the square.
-$$x ^ { 2 } + 8 x = 3$$
A) $\{ - 1 \pm \sqrt { 19 } \}$
B) $\{ - 4 \pm \sqrt { 19 } \}$
C) $\{ 4 + \sqrt { 19 } \}$
D) $\{ - 4 \pm 2 \sqrt { 19 } \}$

Question

Quizplus · Accepted Answer

To complete the square, we need to add $(8/2)^2 = 16$ to both sides of the equation:
$$x^2 + 8x + 16 = 19$$
This can be factored as:
$$(x + 4)^2 = 19$$
Taking the square root of both sides:
$$x + 4 = \pm \sqrt{19}$$
$$x = -4 \pm \sqrt{19}$$
Therefore, the answer is B.

Solve the Equation by Completing the Square x2+8x=3x ^ { 2 } + 8 x = 3x2+8x=3

Solve the Equation by Completing the Square $x ^ { 2 } + 8 x = 3$