Solve by completing the square.
-$$x ^ { 2 } + 16 x = - 43$$
A) $\{ 8 - \sqrt { 43 } , 8 + \sqrt { 43 } \}$
B) $\{ - 16 + \sqrt { 43 } \}$
C) $\{ 8 + \sqrt { 21 } \}$
D) $\{ - 8 - \sqrt { 21 } , - 8 + \sqrt { 21 } \}$

Question

Quizplus · Accepted Answer

To complete the square, rewrite the equation as $x^2 + 16x + 64 = 21$, which gives $(x + 8)^2 = 21$. Solving for $x$, we get $x + 8 = \pm \sqrt{21}$, leading to solutions $x = -8 \pm \sqrt{21}$.

Solve by Completing the Square x2+16x=−43x ^ { 2 } + 16 x = - 43x2+16x=−43

Solve by Completing the Square $x ^ { 2 } + 16 x = - 43$