Respuesta :
You need to find x and then how we have a equality I can to put negative twelve to both sides
X+9+12-12=-3-12
X+9=-15
And the same way with 9
X+9-9=-15-9
X=-24
X+9+12-12=-3-12
X+9=-15
And the same way with 9
X+9-9=-15-9
X=-24