How do you solve $5 x^{2} - 8 x - 4 = 0$ $5x^2−8x−4=0$ using the quadratic formula?

Question

How do you solve $5 x^{2} - 8 x - 4 = 0$ $5x^2−8x−4=0$ using the quadratic formula?

1 Answer

Impact of this question

9084 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2016-06-04T03:07:52

$x = 2$ $x = 2$ , $x = - \frac{2}{5}$ $x = -2/5$

Explanation:

The quadratic formula states that given a quadratic equation

$a x^{2} + b x + c = 0$ $ax^2 + bx + c = 0$

Its roots can be obtained using the equation below

$x = \frac{- b \pm \sqrt{b^{2} - 4 a c}}{2 a}$ $x = (-b +- sqrt(b^2 - 4ac))/(2a)$

$5 x^{2} - 8 x - 4 = 0$ $5x^2 - 8x - 4 = 0$

$\Rightarrow x = \frac{- (- 8) \pm \sqrt{{(- 8)}^{2} - 4 (5) (- 4)}}{2 (5)}$ $=> x = (-(-8) +- sqrt((-8)^2 - 4(5)(-4)))/(2(5))$

$\Rightarrow x = \frac{8 \pm \sqrt{64 + 80}}{10}$ $=> x = (8 +- sqrt(64 + 80))/10$

$\Rightarrow x = \frac{8 \pm \sqrt{144}}{10}$ $=> x = (8 +- sqrt(144))/10$

$\Rightarrow x = \frac{8 \pm 12}{10}$ $=> x = (8 +- 12)/10$

$\Rightarrow x = \frac{20}{10} \Rightarrow x = 2$ $=> x = 20/10 => x = 2$
$\Rightarrow x = - \frac{4}{10} \Rightarrow x = - \frac{2}{5}$ $=> x = -4/10 => x = -2/5$

Science

Math

Humanities

... and beyond

How do you solve $5 x^{2} - 8 x - 4 = 0$ $5x^2−8x−4=0$ using the quadratic formula?

1 Answer

Explanation:

Related questions

Impact of this question

Science

Math

Humanities

... and beyond

How do you solve 5x2−8x−4=05x^2−8x−4=0 using the quadratic formula?

1 Answer

Explanation:

Related questions

Impact of this question

How do you solve $5 x^{2} - 8 x - 4 = 0$ $5x^2−8x−4=0$ using the quadratic formula?