Answer
The fill in the blanks are.
$z $,
add equation (1) and (3).
Work Step by Step
The given equations are
$ x+y+z=2 $ ... (1)
$ 2x-3y=3 $ ... (2)
$ 10y-z=12 $ ... (3)
In the equation (2) the variable $ z $ is missing.
Now add equation (1) and (3).
$ x+y+z+10y-z=2+12 $
$ x+11y=14 $. This is the required equation where the variable $ z $ is missing.
