Question 149622
Like this you mean?
{{{(matrix(2,2,-4,0,1,3))}}}
For a 2x2 general matrix like the following,
{{{(matrix(2,2,a,b,c,d))}}}
The determinant is given by
{{{D=ad-bc}}}
In your case,
{{{D=-4(3)-0(1)}}}
{{{D=-12}}}