D=b²-4*a*c=(6)²-4*9*(-1)=36+36=72=√72
x1=-b+√D/2*a
=-6+√72/2*9=-6+√72/18=-1+√72/3
x2=-b-√D/2*a
=-6-√72/2*9=-6-√72/18=-1-√72/3
D=b²-4*a*c=(6)²-4*9*(-1)=36+36=72=√72
x1=-b+√D/2*a
=-6+√72/2*9=-6+√72/18=-1+√72/3
x2=-b-√D/2*a
=-6-√72/2*9=-6-√72/18=-1-√72/3