Question

Solve for the determinant in the equation below(10marks)

1.7.1

$\begin{matrix} 4 & -3 & 2 \\ 1 & 2 &-2 \\ 2 & -1 & -4\\ \end{matrix}$

1.7.2.

$\begin{matrix} 2 & -2 & 1 \\ 2 & 2 & 1\\ 4 & 1 & 3 \\ \end{matrix}$

Answer 1

1.7.1.

$det A =4·2·(-4) + (-3)·(-2)·2 + 2·1·(-1) - 2·2·2 - 4·(-2)·(-1) - (-3)·1·(-4) = -32 + 12 - 2 - 8 - - 8 - 12 = -50$

1.7.2.

$det A = 2·2·3 + (-2)·1·4 + 1·2·1 - 1·2·4 - 2·1·1 - (-2)·2·3 = 12 - 8 + 2 - 8 - 2 + 12 = 8$