Use the quadratic formula to solve the equation.
-$$2 y ^ { 2 } - 7 y - 9 = 0$$
A) $\left\{ \frac { 2 } { 9 } , 0 \right\}$
B) $\left\{ \frac { 2 } { 9 } , - 1 \right\}$
C) $\left\{ \frac { 2 } { 9 } , 1 \right\}$
D) $\left\{ \frac { 9 } { 2 } , - 1 \right\}$

Question

Quizplus · Accepted Answer

The quadratic formula is $$y = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$$ for a quadratic equation $ax^2 + bx + c = 0$. Here, $a = 2$, $b = -7$, and $c = -9$. Plugging these values into the formula gives $$y = \frac{7 \pm \sqrt{(-7)^2 - 4(2)(-9)}}{2(2)} = \frac{7 \pm \sqrt{49 + 72}}{4} = \frac{7 \pm \sqrt{121}}{4} = \frac{7 \pm 11}{4}$$, which results in $y = \frac{9}{2}$ and $y = -1$, corresponding to choice D.

Use the Quadratic Formula to Solve the Equation 2y2−7y−9=02 y ^ { 2 } - 7 y - 9 = 02y2−7y−9=0

Use the Quadratic Formula to Solve the Equation $2 y ^ { 2 } - 7 y - 9 = 0$