Respuesta :
2y = 18 - 9
2y = 9
y = 9/2
-10s + 5 = 25
-10s = 25 - 5
-10s = 20
s = -20/10
s = -2
2y = 9
y = 9/2
-10s + 5 = 25
-10s = 25 - 5
-10s = 20
s = -20/10
s = -2