Question

x³x³-3x²-9x-5 factorise
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Answer 1

Answer:

Substitute 5 for x in x^3 – 3x^2 – 9x – 5

53 – 3(5)2 – 9(5) – 5 = 125 - 75 - 45 - 5 = 0

So, 5 is zero of the expression x^3 – 3x^2 – 9x – 5

This means (x - 5) is a factor of x^3 – 3x^2 – 9x – 5

Divide x^3 – 3x^2 – 9x – 5 by x - 5

( See the image which I have attached )

This means x^3 – 3x^2 – 9x – 5 = (x - 5) (x2 + 2x + 1) = (x - 5) (x+1)2

Therefore, the factorization of x^3 – 3x^2 – 9x – 5 is (x - 5) (x+1)^2

Answer 2

Answer:

(x+1)(x -5)(x+1)

step-by-step explanation:

X³ - 3x² - 9x - 5

= x³ + x² - 4x² - 4x - 5x - 5

= x²( x + 1) - 4x ( x + 1) - 5(x + 1)

= (x + 1)(x² - 4x - 5)

= (x + 1)(x² -5x + x - 5)

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