x1+x2=3/6=1/2
x1x2=-2/6=-1/3
x1^2+x2^2=(x1+x2)^2-2x1x2
=(1/2)^2-2*(-1/3)
=1/4+2/3
=(3+2*4)/12
=11/12
x1^2x2^2=(x1x2)^2=(-1/3)^2=1/9
所以这个一元二次方程是
x^2-11x/12+1/9=0 两边乘36
36x^2-33x+4=0