If you have the general 3x3 matrix:

the determinant is: 
Which further breaks down to:

Note: , and are determinants themselves. If you need help finding the determinant of 2x2 matrices (which is required to find the determinant of 3x3 matrices), check out this solver
--------------------------------------------------------------
From the matrix , we can see that , , , , , , , , and 
Start with the general 3x3 determinant.
Plug in the given values (see above)
Multiply
Subtract
Multiply
Combine like terms.
======================================================================
Answer:
So , which means that the determinant of the matrix is -1
|