Okay, you just need some facts to get yourself going on this one.

If you have a matrix that we'll call A:

a b

c d

then the INVERSE of it will be

[ 1/ (determinant of A) ] * d -b

-c a

The inverse of a 2x2 matrix - mathcentre

That link above has it all summarised quite nicely.

A matrix is SINGULAR if its determinant is zero.

Once again, I will leave that to you.*give ur workings and clear answer.