Question

x^3 -3x^2-9x-5 factorise​

Answer 1

Now, x³ - 3x² - 9x - 5

= x³ + x² - 4x² - 4x - 5x - 6

= x² (x + 1) - 4x (x + 1) - 5 (x + 1)

= (x + 1) (x² - 4x - 5)

= (x + 1) {x² - (5 - 1) x - 5}

= (x + 1) {x² - 5x + x - 5}

= (x + 1) {x (x - 5) + 1 (x - 5)}

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

which is the required factorization.

Answer 2

To Do :

Factorization

Statement :

x³-3x²-9x-5

Solution :

Find out the common from the statement :

x³-3x²-9x-5

x³+x²-4x²-9x-5

x³+x²-4x²-4x-5x-5

x²(x+1)-4x(x+1) -5(x+1)

(x+1)(x²-4x-5)

The required factorization of the above polynomial is :

(x+1)(x²-4x-5)