Question

factorise x³-3x²-9x-5

Answer 1

let x = - 1
1 - 3 -9×-1 -5
1-3+9-5
0
divide x^3 - 3x^2 -9x -5 by x+1
ans x^2-4x-5
x^2-5x+1x-5. splitting the middle term
x(x-5)+1(x-5)
(x-5) (x+1). ans

Answer 2

Answer:

Step-by-step explanation:

x + 1 is the factor. 

x^3 + x^2 - 4x^2 - 4x - 5x - 5 

x^2 (x + 1) - 4x (x + 1) - 5 (x + 1) 

 (x + 1) (x^2 - 4x - 5) 

(x+1)(x² - 5x + x - 5)

= (x + 1) (x - 5) (x + 1).