Use the quadratic formula to solve the equation.
-$$x ( 5 x + 9 ) = 4$$
A) $\left\{ \frac { - 9 - 1 } { 10 } , \frac { - 9 + 1 } { 10 } \right\}$
B) $\left\{ \frac { 9 - 1 } { 10 } , \frac { 9 + 1 } { 10 } \right\}$
C) $\left\{ \frac { - 9 - \sqrt { 161 } } { 10 } , \frac { - 9 + \sqrt { 161 } } { 10 } \right\}$
D) $\left\{ \frac { 9 - \sqrt { 161 } } { 10 } , \frac { 9 + \sqrt { 161 } } { 10 } \right\}$

Question

Quizplus · Accepted Answer

First, expand and rearrange the equation to standard form: $5x^2 + 9x - 4 = 0$. Applying the quadratic formula, $x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$, with $a = 5$, $b = 9$, and $c = -4$, yields $x = \frac{-9 \pm \sqrt{81 + 80}}{10} = \frac{-9 \pm \sqrt{161}}{10}$.

Use the Quadratic Formula to Solve the Equation x(5x+9)=4x ( 5 x + 9 ) = 4x(5x+9)=4

Use the Quadratic Formula to Solve the Equation $x ( 5 x + 9 ) = 4$