Solve the equation by the method of your choice.
-$$x ^ { 2 } + 12 x + 15 = 0$$
A) $\{ 6 - \sqrt { 15 } , 6 + \sqrt { 15 } \}$
B) $\{ - 12 + \sqrt { 15 } \}$
C) $\{ 6 + \sqrt { 21 } \}$
D) $\{ - 6 - \sqrt { 21 } , - 6 + \sqrt { 21 } \}$

Question

Quizplus · Accepted Answer

The quadratic formula $x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$ is used here. For the equation $x^2 + 12x + 15 = 0$, $a = 1$, $b = 12$, and $c = 15$. The discriminant $b^2 - 4ac = 144 - 60 = 84$. Thus, the solutions are $x = \frac{-12 \pm \sqrt{84}}{2}$, which simplifies to $x = -6 \pm \sqrt{21}$.

Solve the Equation by the Method of Your Choice x2+12x+15=0x ^ { 2 } + 12 x + 15 = 0x2+12x+15=0

Solve the Equation by the Method of Your Choice $x ^ { 2 } + 12 x + 15 = 0$