For which value of `'p', y^(2)+xy+px^(2)-x-2y=0` represents a pair of straight lines

a(x^(2)-y^(2))+xy=0 represents a pair of straight lines for

a(x^(2)-y^(2))+xy=0 represents a pair of straight lines for

Does x^(2)+y^(2)=0 represent a pair of straight lines

If x^(2)+xy-2y^(2)+4x-y+k=0 represents a pair of straight lines, find k.

Find the value of lambda for which the equation 2x^(2)+4xy+y^(2)+x+3y+2=0 represents a pair of straight line

If kx^(2)+10xy+3y^(2)15x21y+18=0 represents a pair of straight lines then k=