If $A=\begin{bmatrix}2&4\\x&\frac{-1}{2}\end{bmatrix}$ and A is singular, then x is equal to:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → $-\frac{1}{4}$
$A=\begin{bmatrix}2&4\\x&\frac{-1}{2}\end{bmatrix}$
A is singular, $|A|=0$
$⇒-1-4x=0$
$⇒x=-\frac{1}{4}$