Question

factorise:
x^3-3x^2-9x-5​

Answer 1

Answer:

x^(3)-3x^(2)-9x-5

Now,

substituting -1 in eq.

[-1^(3)]-3×[-1^(2)]-9×[-1]

=0

since it's satisfy the eq.

Now,

x= -1

or, x+1=0

Now,

x+1 ÷ x^(3)-3x^(2)-9x-5

= x^(2)-4x-5

now, factories it's

x^(2)-4x-5

x^(2)-5x+x-5=0

x(x-5)+1(x-5)=0

or,(x+1)(x-5)=0

x+1=0 or x-5=0

therefore, x= -1 or x=5

Answer 2

Step-by-step explanation:

Given Equation is x^3 - 3x^2 - 9x - 5

= > x^3 - 4x^2 + x^2 - 5x - 4x - 5

= > x^3 - 4x^2 - 5x + x^2 - 4x - 5

= > x(x - 4x - 5) + 1(x^2 - 4x - 5)

= > (x + 1)(x^2 - 4x - 5)

= > (x + 1)(x^2 + x - 5x - 5)

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

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

= > (x + 1)^2(x - 5).

Hope this helps!