Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section A

Chapter

Matrices

Question:

If $\begin{vmatrix} 2 & 4\\5 & 1\end{vmatrix}=\begin{vmatrix}2x & 4\\6 & x\end{vmatrix}$ then, x is equal to :

Options:

1

$2\sqrt{3}$

$±\sqrt{3}$

$±2\sqrt{3}$

Correct Answer:

$±\sqrt{3}$

Explanation:

The correct answer is Option (3) → $±\sqrt{3}$

$\begin{vmatrix} 2 & 4\\5 & 1\end{vmatrix}=\begin{vmatrix}2x & 4\\6 & x\end{vmatrix}$

so $2-20=2x^2-24$

$2x^2=24-20+2$

$2x^2=6$

$x^2=3⇒x=±\sqrt{3}$