Question

x^3-5x^2+8x-4=0

Answer 1

x³ - 5x² + 8x - 4

= x³ - x² - 4x² + 4x + 4x - 4

= x²( x - 1) - 4x (x - 1) + 4 (x - 1)

= (x² - 4x + 4) (x - 1)

= (x - 2)² (x - 1)

x - 1 = 0

x = 1

(x - 2)² = 0

x = 2

vậy x = 1

     x = 2