If a matrix \( A=\begin{bmatrix}x+3 & 3\\2x+1 & 5\end{bmatrix} \) is singular, then the value of x will be
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → \( x=12 \)
A matrix is singular when its determinant is zero.
\( \displaystyle |A|=\begin{vmatrix}x+3 & 3\\2x+1 & 5\end{vmatrix} \)
\( \displaystyle =5(x+3)-3(2x+1) \)
\( \displaystyle =12-x \)
\( \displaystyle 12-x=0 \)
\( \displaystyle x=12 \)