Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Matrices

Question:

Options:

a

b

c

d

Correct Answer:

c

Explanation:

$\begin{bmatrix}1&x\end{bmatrix}\begin{bmatrix}2&-1\\1&2\end{bmatrix}\begin{bmatrix}1\\3\end{bmatrix}=[0]$

$⇒\begin{bmatrix}1&x\end{bmatrix}\begin{bmatrix}-1\\7\end{bmatrix}=[0]$

$⇒\begin{bmatrix}-1+7x\end{bmatrix}=[0]$

$⇒x=\frac{1}{7}$