If \(\begin{vmatrix}3x & 7\\ 4 & x\end{vmatrix}=\begin{vmatrix}6 & -2\\ 4 & 2\end{vmatrix}\), then the value of x is :
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → \(\pm 4\)
Expanding both 2 × 2 determinants:
\(3x\cdot x - 7\cdot 4 = 6\cdot 2 - (-2)\cdot 4\)
\(3x^2 - 28 = 20\)
\(3x^2 = 48\)
\(x^2 = 16\)
\(x = \pm 4\)