Question

factorise the following....
pls help me guys...​

Answer 1

By Hit and trial we get -1 as a root of this cubic

So (x+1) is factor of it

Now, dividing the cubic by x+1 ; we get

(x²-4x-5)

⇒ x³ - 3x² - 9x -5 = (x+1)(x²-4x-5)

⇒ x³ - 3x² - 9x -5 =(x+1)(x-5)(x+1)

⇒ x³ - 3x² - 9x -5 =(x+1)²(x-5)

Final Answer:

(x+1)²(x-5)

Answer 2

By Hit and trial we get -1 as a root of this cubic

So (x+1) is factor of it

Now, dividing the cubic by x+1 ; we get

(x²-4x-5)

⇒ x³ - 3x² - 9x -5 = (x+1)(x²-4x-5)

⇒ x³ - 3x² - 9x -5 =(x+1)(x-5)(x+1)

⇒ x³ - 3x² - 9x -5 =(x+1)²(x-5)

Final Answer:

(x+1)²(x-5)