Determine the Most Efficient Method to Use When Solving a Quadratic Equation
Solve the equation by the method of your choice.
-$$( 2 x + 9 ) ^ { 2 } = 64$$
A) $\left\{ - \frac { 17 } { 2 } , - \frac { 1 } { 2 } \right\}$
B) $\left\{ \frac { 1 } { 2 } , \frac { 17 } { 2 } \right\}$
C) $\left\{ - \frac { 1 } { 2 } , 0 \right\}$
D) $\left\{ \frac { 55 } { 2 } \right\}$

Question

Quizplus · Accepted Answer

First, take the square root of both sides to get $2x + 9 = \pm 8$. Solving the two resulting equations $2x + 9 = 8$ and $2x + 9 = -8$ gives $x = -\frac{1}{2}$ and $x = -\frac{17}{2}$, respectively.