The pair of equations x + 2y + 5 = 0 and –3x – 6y + 1 = 0 have
(A) a unique solution
(B) exactly two solutions
(C) infinitely many solutions
(D) no solution
Answer: D
Solution:
In equation
x + 2y + 5 = 0
a1 = 1, b1 = 2, c1 = 5
In equation
–3x –6y + 1 = 0
a2 =–3, b2 = –6, c2 = 1
Here
Hence these lines are parallel to each other and have no solution.