Okay, you just need some facts to get yourself going on this one.
If you have a matrix that we'll call A:
then the INVERSE of it will be
[ 1/ (determinant of A) ] * d -b
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.