Jawabanmu

2014-06-13T05:56:09+07:00
1/f = 1/S' + 1/S Itu rumus umum
1/s = 1/f - 1/s'
atau bisa pake cara s= s' x f/ s' - f jadi, 4.8/ 4-8 = 32/ -4
s = -8
2014-06-13T09:02:37+07:00
1/f=1/s+1/s'
1/s=1/8-1/4
1/s=(1-2)/8
1/s=-1/8
s=-8 cm