Solve the equation by completing the square.
-$x ^ { 2 } + x + 9 = 0$
A) $\frac { 1 - \sqrt { 35 } } { 2 } , \frac { 1 + \sqrt { 35 } } { 2 }$
B) $\frac { 1 - \mathrm { i } \sqrt { 35 } } { 2 } , \frac { 1 + \mathrm { i } \sqrt { 35 } } { 2 }$
C) $\frac { - 1 - \sqrt { 35 } } { 2 } , \frac { - 1 + \sqrt { 35 } } { 2 }$
D) $\frac { - 1 - i \sqrt { 35 } } { 2 } , \frac { - 1 + i \sqrt { 35 } } { 2 }$

Question

Quizplus · Accepted Answer

Completing the square for $x^2 + x + 9 = 0$ gives $(x + \frac{1}{2})^2 = -\frac{35}{4}$. Solving for $x$ results in complex solutions $\frac{-1 \pm i\sqrt{35}}{2}$.

Solve the Equation by Completing the Square x2+x+9=0x ^ { 2 } + x + 9 = 0x2+x+9=0

Solve the Equation by Completing the Square $x ^ { 2 } + x + 9 = 0$