Let $\begin{vmatrix}x&2\\18&x\end{vmatrix}=\begin{vmatrix}-4&-2\\-8&-4\end{vmatrix}$. Then (A) $x = -4$ Choose the correct answer from the options given below: |
(A) and (C) only (C) only (D) only (B) and (D) only |
(B) and (D) only |
The correct answer is Option (4) → (B) and (D) only Given: $\begin{vmatrix} x & 2 \\ 18 & x \end{vmatrix} = \begin{vmatrix} -4 & -2 \\ -8 & -4 \end{vmatrix}$ Evaluate both determinants. Left side: $x\cdot x - 18\cdot 2 = x^{2} - 36$ Right side: $(-4)(-4) - (-8)(-2) = 16 - 16 = 0$ Hence: $x^{2} - 36 = 0$ $x^{2} = 36$ $x = \pm 6$ From options, $x=-6$ and $x=6$ satisfy. Final answer: $x=-6$ and $x=6$ |