Which of the following equation does not represent a pair of lines ?
A)
B)
C)
D)

Solution:

Explanation:
(A)


and
Therefore, it represents a pair of lines and
(B)

and
Therefore, it represents a pair of lines and
(C)
which represents parabola
(D)

Therefore, it represents a pair of lines and
As a result, only (C) does not represents a pair of lines.