Which of the following second , degree eqation represented a pair of straight lines ?

Which of the following equation does not represent a pair of lines ?

Which of the following equation does not represent a pair of lines ?

Angle between pair of straight line

Which one of the following differential equations represents the family of straight lines which are at unit distance from the origin ?

Which of the following equations represents a pair of real and coincident straight lines?

Which of the following equations represents a pair of real and coincident straight lines?

Which of the following pairs does not represent a pair of isomers?

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

The equation 16x^(4)-y^(4)=0 represents a pair of straight lines

Every first degree equation in x, y represents a straight line.