Jawapan

2016-08-10T18:40:12+08:00
Hrp awak phm dgn jln kira saya
sorry..jap 1/f - 1/v = 1/u 1(v)/f(v) - 1(f)/v(f) = 1/u v-f/fv = 1/u u = fv/v-f