7,8,9 Cara+ Jawaban Tolong

7. (d) di titik M
8. 1/f = 1/s + 1/s' = 1/6 + 1/30 = 5/30 +1/30 =6/30
f = 30/6 = 5 cm (b)
9. 1/f = 1/s + 1/s'
1/s' = 1/f - 1/s = 1/180 - 1/60 = 1/180-3/180= -2/180
s'= -180/2 = -90 cm (b)