Answer :

mathstudent55

Answer:

[tex] x = \dfrac{2}{5} + \dfrac{\sqrt{14}}{5} [/tex]   or   [tex] x = \dfrac{2}{5} - \dfrac{\sqrt{14}}{5} [/tex]

Step-by-step explanation:

[tex] 5x^2 - 2 = 4x [/tex]

[tex] 5x^2 - 4x - 2 = 0 [/tex]

[tex] x = \dfrac{-b \pm \sqrt{b^2 - 4ac}}{2a} [/tex]

[tex] x = \dfrac{-(-4) \pm \sqrt{(-4)^2 - 4(5)(-2)}}{2(5)} [/tex]

[tex] x = \dfrac{4 \pm \sqrt{16 + 40}}{10} [/tex]

[tex] x = \dfrac{4 \pm 2\sqrt{14}}{10} [/tex]

[tex] x = \dfrac{2 \pm \sqrt{14}}{5} [/tex]

[tex] x = \dfrac{2}{5} + \dfrac{\sqrt{14}}{5} [/tex]   or   [tex] x = \dfrac{2}{5} - \dfrac{\sqrt{14}}{5} [/tex]

saralansiva

Answer:

Answer:

x = \dfrac{2}{5} + \dfrac{\sqrt{14}}{5}x=

5

2

+

5

14

or x = \dfrac{2}{5} - \dfrac{\sqrt{14}}{5}x=

5

2

−

5

14

Step-by-step explanation:

5x^2 - 2 = 4x5x

2

−2=4x

5x^2 - 4x - 2 = 05x

2

−4x−2=0

x = \dfrac{-b \pm \sqrt{b^2 - 4ac}}{2a}x=

2a

−b±

b

2

−4ac

x = \dfrac{-(-4) \pm \sqrt{(-4)^2 - 4(5)(-2)}}{2(5)}x=

2(5)

−(−4)±

(−4)

2

−4(5)(−2)

x = \dfrac{4 \pm \sqrt{16 + 40}}{10}x=

10

4±

16+40

x = \dfrac{4 \pm 2\sqrt{14}}{10}x=

10

4±2

14

x = \dfrac{2 \pm \sqrt{14}}{5}x=

5

2±

14

x = \dfrac{2}{5} + \dfrac{\sqrt{14}}{5}x=

5

2

+

5

14

or x = \dfrac{2}{5} - \dfrac{\sqrt{14}}{5}x=

5

2

−

5

14

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