Question

ii) x2 + 6 x- 8 = 0 soving the formula method​

Answer 1

ANSWER:

Given:

• x^2 + 6x - 8 = 0

To Find:

• Value of x

Solution:

We are given that,

$\implies x^2+6x-8=0$

We know that, by Quadratic Formula,

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

Here,

• a = 1
• b = 6
• c = -8

So,

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

$\implies x=\dfrac{-6\pm\sqrt{6^2-4(1)(-8)}}{2(1)}$

$\implies x=\dfrac{-6\pm\sqrt{36+32}}{2}$

$\implies x=\dfrac{-6\pm\sqrt{68}}{2}$

$\implies x=\dfrac{-6\pm2\sqrt{17}}{2}$

$\implies x=\dfrac{2(-3\pm\sqrt{17})}{2}$

$\implies\bf x=-3\pm\sqrt{17}$

Therefore value of x is -3 + √7 and -3 - √7.

Formula Used:

• Quadratic Formula,: $\hookrightarrow x=\dfrac{-b\pm\sqrt{b^2-4ac}}{2a}$