Use the quadratic formula to find the exact solutions.
-$$3 x ^ { 2 } - 20 x - 7 = 0$$
A) $- \frac { 1 } { 3 } , 7$
B) $- \frac { 1 } { 7 } , 3$
C) $- 3,7$
D) $- \frac { 1 } { 7 } , - 3$

Question

Quizplus · Accepted Answer

The quadratic formula is $$x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$$ for a quadratic equation $ax^2 + bx + c = 0$. Here, $a = 3$, $b = -20$, and $c = -7$. Plugging these into the formula gives $$x = \frac{20 \pm \sqrt{(-20)^2 - 4(3)(-7)}}{2(3)} = \frac{20 \pm \sqrt{400 + 84}}{6} = \frac{20 \pm \sqrt{484}}{6} = \frac{20 \pm 22}{6}$$, which simplifies to $x = -\frac{1}{3}$ or $x = 7$.

Use the Quadratic Formula to Find the Exact Solutions 3x2−20x−7=03 x ^ { 2 } - 20 x - 7 = 03x2−20x−7=0

Use the Quadratic Formula to Find the Exact Solutions $3 x ^ { 2 } - 20 x - 7 = 0$