Write this:

 and 

First fill in both denominators with the
coefficients as they appear left of the equal signs, like this

 and 

Now since  appears FIRST in the problem, fill in
the FIRST column for x with the numbers on the right of the
equal sign, namely these: 

 and 

Now since  appears SECOND in the problem, fill in
the SECOND column for y with the numbers on the right of the
equal sign, namely these: 

 and 

Complete the determinants by bringing the columns below up
to the top:

 and 

To evaluate , use this formula.
which amounts to subtracting the diagonal products:

  





Now for y.  We only have to do the top
determinant because we have already done
the bottom determinant, and found it to be 13, so



Edwin