Respuesta :

s-3f=-24
-3f=-24-s
3f=24+s
f=24+s/3
Espeon
I'm not sure if the s was supposed to be an f, but if it was an f, then:
f=3f-24
-3f  -3f    (what you do to one side you do to the other)
-----------
-2f=-24
Divide both sides by -2
f=12