Respuesta :

Answer:

s = -9

Step-by-step explanation:

9 + s =0

Subtract 9 from each side

9 -9+ s =0-9

s = -9

Answer:

-9

Step-by-step explanation:

9 + s = 0

subtract 9

9 + s - 9 = 0 - 9

simplify

s = -9