<u>ANSWER </u>
<u>EXPLANATION</u>
We the have the equations,
Multiplying through by negative one gives,
Also
and
Dividing through by 2 gives
Making z the subject gives,
Now we substitute equation (3) into equation (1) and (2)
Equation (3) in to equation (1) gives,
This implies that;
We now put equation (3) in (2) to get,
This implies that
But
So,
Dividing through by negative 9 gives
and
Therefore