Respuesta :

12.
b/4=3/2
timbes both sides by 4
b=12/2
b=6

15.
3/14=(s-2)/21
times both sides by 21
63/14=s-2
4.5=s-2
add 2 to both sides
6.5=s
or 13/2=s

18.
can't see number below 52