Question

If the system of equation 2x + 5y + 8z = 0, x + 4y + 7z = 0, 6x + 9y – λz = 0 has a non-trivial solution, then λ is equal to

• A. 12
• B. –12
• C. 0
• D. None of these.

Answer 1

Answer: (B)

–12

Answer 2

$\left| \begin{matrix} 2 & 5 & 8 \\ 1 & 4 & 7 \\ 6 & 4 & - \lambda \end{matrix} \right| = 0$ ⇒ λ = -12.