3x^2-4x+1=0
(x-1)(3x-1)=0
x1=1,x2=1/3
y^2-y-4=0
y1=(1+√17)/2,y2=(1-√17)/2
4x^2-4x+1=0
(2x-1)^2=0
x=1/2
-2t^2-2t=0
t(t+1)=0
t1=0,t2=-1
3x^2-12x+9=0
(x-1)(3x-9)=0
x1=1,x2=9/3
1/2x^2+3x+9/2-2=0
x^2+6x+5=0
(x+1)(x+5)=0
x1=-1,x2=-5