4x-6x^2=0
-6x^2+4x=0
6x^2-4x=0 [:2]
3x^2-2x=0 a=3, b=-2, c=0
D=b^2-4ac=(-2)^2-4*3*0=(-2)^2=4
x1=(-b+sqrt(D))/(2a)=(-(-2)+sqrt(4))/(2*3)=(2+2)/6=4/6=2/3
x2=(-b-sqrt(D))/(2a)=(-(-2)-sqrt(4))/(2*3)=(2-2)/6=0/6=0
x1+x2=-b/a
2/3+0=-(-2)/3=2/3
x1x2=ca
2/3*0=3*0=0