Determinant of $$$\left[\begin{array}{cc}4 & 5\\7 & 8\end{array}\right]$$$

The calculator will find the determinant of the square $$$2$$$x$$$2$$$ matrix $$$\left[\begin{array}{cc}4 & 5\\7 & 8\end{array}\right]$$$, with steps shown.

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Your Input

Calculate $$$\left|\begin{array}{cc}4 & 5\\7 & 8\end{array}\right|$$$.

Solution

The determinant of a 2x2 matrix is $$$\left|\begin{array}{cc}a & b\\c & d\end{array}\right| = a d - b c$$$.

$$$\left|\begin{array}{cc}4 & 5\\7 & 8\end{array}\right| = \left(4\right)\cdot \left(8\right) - \left(5\right)\cdot \left(7\right) = -3$$$

Answer

$$$\left|\begin{array}{cc}4 & 5\\7 & 8\end{array}\right| = -3$$$A