Question

Find the values of followling determine
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Answer 1

To solve given det.

$\left|\begin{array}{cc} - 1& 7 \\2 &4\end{array}\right|$

Solution:-

For solving determinant of 2x2 simply multiply even sum diagonal elements and subtract the product of odd sum diagonal elements.

$\left|\begin{array}{cc} - 1& 7 \\2 &4\end{array}\right| = - 1 \times 4 - (7\times 2)$

$\left|\begin{array}{cc} - 1& 7 \\2 &4\end{array}\right| = -18$

$\huge\boxed{\red{answer = - 18}}$