x^3 - 9X^2 +19x -11 =0
<=> (x^3 - x^2) - (8x^2 - 8x) +(11x-11)=0
<=> x^2(x-1) - 8x(x-1) + 11(x-1)=0
<=> (x-1)(x^2-8x+11) = 0
<=> x-1=0
<=> x=1
9x^3 - 6x^2 +12x=8
<=> 9x^3-6x^2+12x-8=0
<=. 3x^2(3x-2) + 4(3x-2)=0
<=> (3x-2)(3x^2 +4 ) =0
<=> 3x-2 = 0 (do 3x^2 +4 >= 4 >0)
<=> x= 2/3