Jawabanmu

2014-05-29T21:26:10+07:00
1/f= 1/s+1/s'
1/20= 1/30 + 1/s'
3/60 - 2/60 = 1/s'
60 = s'

perbesaran = 60/ 30 = 2kali
klo kurang paham komen aja
terima kasih
sama2
2014-05-29T21:32:50+07:00
Jarak bayangan
1/f = 1/s + 1/s'
1/20 = 1/30 + 1/s'
samakan jadi per 60
3-2/60 = 1/s'
1/60 = 1/s'
s' = 60
perbesaran
M = garis mutlak s'/s
= 60/30
= 2 Kali