The equation to the pair of lines passing through the origin and perpendicular to `5x^2 + 3xy = 0`

The equation of the pair of lines passing through the origin and perpendicular to the pair 10 x^(2)+4 x y-2 y^(2)=0 is

The equation to the pair of lines through the origin and perpendicular to 5 x^(2)-y^(2)=0 is

The combine equation of the lines passing through the origin and perpendicular to the lines x+2y=19 and 3x+y=18 is

Combined equation of the lines passing through the origin and perpendicular to the lines 2x^(2)-3xy+y^(2)=0 is