The augmented matrix is:

Now subtract the first row from the second and third rows and add it to the third row to get:

Now interchange the last row with the second row:

Now because the last two rows are identical it means that one of the variables will be indeterminate, and we might as well let this be . We also observe that the last two rows mean that .

Now substituting into the equation corresponding to our second row:

so:

Now substituting into the equation corresponding to our first row:

so:

CB