Question

Find the roots of the quadratic equation x^2 - 8x - 20 = 0 by factorisation
method.​

Answer 1

first factor the quadratic by considering the factors of - 20 which sum to8.

These are - 10 and +2

⇒x2 − 8x−20= (x−10) (x+2) =0

=hence (x - 10 ) = 0

⇒x=10 or (x+2) = 0⇒x=−2

Answer 2

$Given \: Quadratic \: equation :$

$x^{2} - 8x - 20 = 0$

/* Splitting the middle term, we get */

$\implies x^{2} + 2x - 10x - 20 = 0$

$\implies x(x+2) -10(x+2) = 0$

$\implies (x+2)(x-10) = 0$

$\implies x+2 = 0 \:Or \: x-10= 0$

$\implies x = -2 \: Or \:x = 10$

Therefore.,

$\green { x = -2 \: and \:x = 10}$

•••♪