Question

solve the equation by formula method: x^2-8x+1=0​

Answer 1

Answer:

Step-by-step explanation:

Given,

$x^2 - 8x + 1 = 0$

To Find :-

Value of 'x'

Solution :-

Method 1 :-[Formulae Method]

Comparing given equation "$x^2 - 8x + 1 = 0$" with general form of quadratic equation "$ax^2 + bx + c = 0$" :-

$\implies a = 1, b = -8,c = 1$

Formulae Required :-

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

Let's do :-

Substituting Values :-

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

$x = \dfrac{8 \pm\sqrt{64 - 4}}{2}$

$x = \dfrac{8 \pm \sqrt{60}}{2}$

$x = \dfrac{8 \pm \sqrt{4\times 15}}{2}$

$x = \dfrac{8 \pm 2\sqrt{15}}{2}$

$x = \dfrac{2(4 \pm \sqrt{15})}{2}$

$x = 4\pm \sqrt{15}$

$x = 4 + \sqrt{15} , 4 - \sqrt{15}$