Question

factorise x^3-2x^2-5x-2

Answer 1

x³-2x²-5x-2
= x³ + x² - 3x²- 3x - 2x -2
= x²(x+1) - 3x(x+1) -2(x+1)
= (x+1)(x²-3x-2)
= (x+1)(x²-2×3x/2+9/4-(17/4))
= (x+1)(x-3/2)²-(17/4))
= (x+1)(x-3/2-√17/2)(x-3/2+√17/2)