Question

fastorise:x^3-3^2-9x-5​

Answer 1

Step-by-step explanation:

${x}^{3 } - 3x^{2} - 9x - 5 \\ By \: observtion \: we \: find \: that \: at \: x = - 1 \\ function \: become \: zero \: hence \\ (x + 1) \: will \: a \: fctor \\ x^{2} (x + 1) - 4x(x + 1) - 5(x + 1) \\ (x + 1)( {x}^{2} - 4x - 5) \\ (x + 1)( {x }^{2} - 5x + x - 5) \\ (x + 1)[x(x - 5) + 1(x - 5)] \\ (x + 1)(x + 1)(x - 5)$

This is required ans..

Answer 2

Answer:

(x+1)²(x-5)

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

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

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

=(x+1)²(x-5)

Hope it helps you!!