Question

please help me in this question ​

Answer 1

x³ - 3x² - 9x - 5

= x³ - 5x² + 2x² - 10x + x - 5

= x²(x - 5) + 2x(x - 5) + 1(x - 5)

= (x - 5)(x² + 2x + 1)

= (x - 5)(x² + x + x + 1)

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

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