Verified answer

12x^3-16x^2+7x-1=0

12x^3 - 12x^2 - 4x^2 + 3x + 4x - 1 =0

12x^3 - 12x^2 + 3x - 4x^2 + 4x - 1 =0

3x(4x^2 - 4x +1) - 1*(4x^2 - 4x + 1) = 0

(3x-1)(4x^2-4x+1)=0

(3x-1)(2x-1)^2=0

x=1/3

x=1/2