matrix/determinant

[niqueboyd]

am i suppose 2 multipy r12 then r23

(1 pt) Given the matrix
?1 3 0
3 0 0
3 4 ?2

find its determinant.
The determinant is :

 

[tkhunny]

I'd try Expansion by Minors along the middle row. Don't forget the negative sign in the front.