The equation 2x2+3y2−8x−18y+35=k represents
no locus if k>0
an ellipse if k>0
a point if k=0
a hyperbola if k>0
We have
2x2+3y2−8x−18y+35=kor 22x2−4x+3y2−6y+35=kor 2(x−2)2+3(y−3)2=kfor k=0, we get 2(x−2)2+3(y−3)2=0
which represents the point (2,3).