general math MCQ #212

In the system of equations ax+2y=5 and 3x-6y=20, a is a constant. If the system has one solution, which of the following CANNOT be the value of a?

general math MCQ #212

  1. Question 1

    Q1. In the system of equations ax+2y=5 and 3x-6y=20, a is a constant. If the system has one solution, which of the following CANNOT be the value of a?

    • A) -1
    • B) 1
    • C) 2
    • D) -3

    Answer: -1

    Explanation: For a unique solution, lines must not be parallel; the system is parallel when a/3 = 2/(−6), i.e., a = −1, so a = −1 cannot be the value.