Question

If $\left| \begin{matrix} x+7 & 5 \\\ x+-3 & 3 \\\ \end{matrix} \right|=26,$ then x is equal to

• A. $1$
• B. $3$
• C. $5$
• D. $7$

Answer 1

Answer: (C)

$5$

Answer 2

Given, $\left| \begin{matrix} x+7 & 5 \\\ x-3 & 3 \\\ \end{matrix} \right|=26$
$\Rightarrow$ $3(x+7)-5(x-3)=26$
$\Rightarrow$ $3x+21-5x+15=26$
$\Rightarrow$ $-2x+36=26$
$\Rightarrow$ $2x=10$
$\Rightarrow$ $x=5$