Jawabanmu

2013-12-05T18:49:54+07:00
P = jumlah siswa perempuan

7,25 = 20x7,5 + 7,0p : 20 + p
7,25 (20+p) = 150 + 7,0p
145 + 7,25p = 150 + 7,0p
0,25p = 5
p = 20