Respuesta :

4(-1) + 2y = 16
-4 + 2y = 16
2y = 20
y = 10

I think this is how u do it..
4x + 2y = 16
4(-1) + 2y = 16
-4 + 2y = 16
+4 +4
2y = 20
/2 /2
y = 10