# Help with Determinants [closed]

Okay so i understand the first det, which is why i got the correct solution. However for the second det, im not sure how to solve it since because of the different coefficents (0,2,4) and i tried of different solutions. If anyone can give me a clear way to solve these it would be appreciated. Thank You.

• this is a math, but not, as is, a signal processing question, and thus, off-topic here. – Marcus Müller Jun 7 '17 at 22:19

If you open the determinants along the middle column, we get for the first determinant:

$-(bf-ec) + (af-cd) -(ae-bd) = -3$ $\hspace{1cm}$ $[1]$

And for the second determinant, we get

$-(bf-ec) + 2(af-cd) -3(ae-bd) = -2$ $\hspace{1cm}$ $[2]$

The required determinant is

$2(af-cd) -4(ae-bd)$ $\hspace{1cm}$

Which is just $2*([2] - [1])$, which boils down to $2$.