Question

The value of determinant
|2 −4
7 −15| =…………

Answer 1

Answer:

the determinant of the matrix $\left[\begin{array}{cc}2&-4&\\7&-15\end{array}\right]$  is -2.

Step-by-step explanation:

The determinant of a square matrix of dimension two is given by,

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

The given matrix is,

$\left[\begin{array}{cc}2&-4&\\7&-15\end{array}\right]$

So the determinant using the above formula is,

$\left|\begin{array}{cc}2&-4&\\7&-15\end{array}\right| = 2\times (-15)-7\times (-4) = -30-(-28)=-30+28=-2$

Thus the determinant of the given matrix is -2.