[" 3.The equation "(x+y)^(2)-(x^(2)+y^(2))=],[0" represents "]

The equation (x+y+1)^(2)+k(x^(2)+y^(2)+1)=0 represents two straight lines then one of the possible values of k is

The equation x^(2)y^(2)-9y^(2)-6x^(2)y+54y=0 represents

The equation x^(2)y^(2)-9y^(2)-6x^(2)y+54y=0 represents

The equation x^(2)y^(2)-9y^(2)-6x^(2)y+54y=0 represents

The equation (x-5)^(2)+(x-5)(y-6)-2(y-6)^(2)=0 represents

The equation (x-5)^(2)+(x-5)(y-6)-2(y-6)^(2)=0 represents

Equation x^(2)y^(2)-9y^(2)+6x^(2)y-54y=0 represents

The equation x^(2) + y^(2) + z^(2) = 0 represents

Equation y^(2)-x^(2)+2x-1=0 represents