Respuesta :

Solve for z:-

z - 12 = -9
z = ?
Inverse Operation
-9 + 12 = z
-9 +12 = 3
z = 3

Check:-
z - 12 = -9
z = 3
3 - 12 = ?
3 - 12 = -9
Correct!

z = -9
z - 12 = -9
Inverse operation ( + 12 to both sides)

z = -9 + 12
z = 3

z would equal 3