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