Question

19. Factorise:
(i) (x)2 - x - 20​

Answer 1

Answer:

the answer is given below

Step-by-step explanation:

splitting the middle term ,

x² + 5x - 4x - 20 = 0

x( x + 5 ) - 4( x + 5 ) = 0

( x + 5 )( x - 4 ) = 0

x + 5 = 0 or x - 4 = 0

x = -5 or x = 4

Therefore ,

Roots of given quadratic equation are -5 , 4

I hope this helps you.

: )

Answer 2

$factorise \\ {x}^{2} - x - 20$

Solution :-

$= > {x}^{2} - x - 20 \\ \: \: \: \: \: \: = > {x}^{2} - (5 - 4)x - 20 \\ \: \: \: \: \: \: \: = > {x}^{2} - 5x + 4x - 20 \\ \: \: \: \: \: \: = > x(x - 5) + 4(x - 5) \\ = > (x - 5)(x + 4)$

Hence,(X-5)(X+4) is the factor