The pairs of straight lines `x^2-3xy+2y^2=0` and `x^2-3xy+2y^2+x-1` form a

The pair of straight line x^2-3xy+2y^2=0 and x^2-3xy+2y^2+x-2=0 from a :

The equations of the diagonals of the square formed by the pairs of straight lines 3x^(2)+8xy-3y^(2)=0 and 3x^(2)+8xy-3y^(2)+2x-4y-1=0 are

The pair of lines 2x^(2)+3xy+5y^(2)=0 and 4x^(2)+21xy+25y^(2)=0 are

Angle between the pair of straight lines x^(2) - xy - 6y^(2) - 2x + 11y - 3 = 0 is

The figure formed by the pairs of lines 2x^(2)+3xy-2y^(2)=0 and 2x^(2)+3xy-2y^(2)-5x+15y-25=0 is a

The figure formed by the pair of lines 2x^2+3xy-2y^2=0 and 2x^2+3xy-2y^2-5x+15y-25=0 is

If the pair of straight lines xy - x - y + 1 = 0 and the line ax+2y-3 = 0 are concurrent then a=