Jawabanmu

2014-06-09T16:49:00+07:00
1/f = 1/so+1/si
1/15 = 1/30 + 1/si
2/30 -1/30 = 1/si
1/30 = 1/si
30 = si

si/so = ti/to
30/30 =10/x
1=10/x
x=10
2014-06-09T16:53:15+07:00
1/f=1/s+1/s' => 1/s' = 1/f-1/s
1/s' = 1/15-1/30 = 2-1/30 = 1/30 = 30

M= s'/s = 30/30 = 1
M= h'/h => h = h'/M = 10/1 = 10