Question

factorise -
${x}^{3} - {10 x }^{2} - 53x - 42$

Answer 1

x³ - 10x² - 53x - 42
= x³ + x² - 11x² - 11x - 42x - 42 
= x²(x + 1) - 11x(x + 1) - 42(x + 1) 
= (x + 1)(x² - 11x - 42)
= (x + 1)(x² - 14x +3x - 42)
= (x + 1){x(x - 14) + 3(x - 14) }
= (x + 1)(x + 3)(x - 14)