[" The equation "],[x^(2)-7xy-y^(2)=0" represents "]

If the equation 7x^(2)-kxy-7y^(2)=0 represents the bisectors of angles between the lines 2x^(2)-7xy+4y^(2)=0 then: k=

Prove that the equation 2x^(2)+xy-6y^(2)+7y-2=0 represents a pair of straight lines.

The equation 12x^(2)+7xy-12y^(2)-18x+y+6=0 represents

The equation 12x^(2)+7xy+ay^(2)+13x-y+3=0 represents a pair of perpendicular lines. Then, the value of a is

If the equation x^(2)+3xy+2y^(2)+x-y+k=0 represents a pair of line, then k=

The equation x^(2)+4xy+4y^(2)-3x-6y-4=0 represents a

The equation x^(2)+4xy+4y^(2)-3x-6y-4=0 represents a

The equation x^(2) + y^(2) - 2xy -1 =0 represents :

The equation x^(2) + y^(2) - 2xy -1 =0 represents :