Question 38
If the expression $$
\begin{vmatrix}a&c\\d&b\end{vmatrix}
$$ has the value $ab-cd$ for all values of $a,$ $b,$ $c,$ and $d,$ then the equation $$
\begin{vmatrix}2x&1\\x&x\end{vmatrix}=3
$$
\begin{vmatrix}a&c\\d&b\end{vmatrix}
$$ has the value $ab-cd$ for all values of $a,$ $b,$ $c,$ and $d,$ then the equation $$
\begin{vmatrix}2x&1\\x&x\end{vmatrix}=3
$$