Question

If $\left(13\right)\left|\begin{array}{cc}2x-1& 6\\ 9& 7\end{array}\right|=p$ then find the value of $p$

• A. $182x-793$
• B. $188x-27$
• C. $182x-385$
• D. $188x-289$

Answer 1

The correct option is A $182x-793$

$p=\left(13\right)\left|\begin{array}{cc}2x-1& 6\\ 9& 7\end{array}\right|=13\left[\right(2x-1)7-6\cdot 9]$

$=13(14x-7-54)=13(14x-61)=182x-793$

Note: $\left|\begin{array}{cc}a& b\\ c& d\end{array}\right|=ad-bc$