How to find zeros a cubic polynomial

x³-4x²+5x-2

x³ - 4x² + 5x -2

let x=1

we get (1)³ - 4(1)² + 5*1 -2

 =  1-4+5-2

= 6-6

= 0

Hence,  (x-1) is the factor of the polynomial

  x² - 3x + 2

  x -1  x³ - 4x² + 5x - 2

  x³ -  x²

  (-)  (+) 

  -3x² +5x -2

  -2x² +3x

  (+)  (-)

  2x – 2

   2x – 2

  (-)  (+)

  0

So, (x-1) (x² - 3x +2)

 (x-1)( x²-2x-x+2)

(x-1)(x(x-2)-1(x-2))

(x-1)(x-1)(x-2)

Hence the zeroes of the polynomial

Are x-1 = 0  , x= 1

  x-1 = 0 ,  x= 1

  x – 2 = 0 , x= 2

zeroes are(1,1,2)