Question

х2 - 6х + 8 = O find its roots​

Answer 1

Answer:

The roots are 2 and 4

Step-by-step explanation:

By factorisation :

x² – 6x + 8 = 0

x² – 2x – 4x + 8 = 0

x(x – 2) – 4(x – 2) = 0

(x – 4) (x – 2) = 0

• x – 4 = 0 ; x = +4
• x – 2 = 0 ; x = +2

The roots are 2 and 4.

By quadratic formula :

For a quadratic equation of the form ax² + bx + c = 0 ; the roots are

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

For the given quadratic equation,

a = 1

b = –6

c = 8

$\sf x = \dfrac{-(-6) \pm \sqrt{(-6)^2-4(1)(8)}}{2(1)} \\ \sf x = \dfrac{6 \pm \sqrt{36-32}}{2} \\ \sf x = \dfrac{6 \pm \sqrt{4}}{2} \\ \sf x = \dfrac{6 \pm 2}{2} \\ \sf x = \dfrac{2(3 \pm 1)}{2} \\ \sf x = 3 \pm 1 \\ \sf x= (3+1) , (3-1) \\ \sf x = 4,2$

The roots are 2 and 4.