Jawabanmu

2014-06-04T13:10:30+07:00
1/f=1/s + 1/s'
1/f - 1/s = 1/s'
f-s/fs = 1/s' = fs/f-s = s'
2.3/2-3 = -6 kalau s' = -(Negatif bayangannya maya,tegak) 
Semoga membantu

2014-06-04T13:30:27+07:00
Diket: So : 3 cm  f : 2cm
dit : Si (jarak bayangan)
1/Si = 1/f -1/So =1/2 -1/3 =1/6
jadi Si = 6 cm