Question

Tlg bantu pake cara ya. tq

Answer 1

DIKET = rata2 smw = 5
nilai siswa baru = 7
rata2 baru = 5.1
DITA = jml siswa smula
JWB = misal, jml siswa smla = X
jml nilai siswa smula = Y
rumus dasar : Rata2 = jml nilai / byk siswa

*) 5 = Y/X
Y = 5X
*) 5.1 = Y + 7 / X + 1
5.1 ( X + 1 ) = Y + 7
Y = 5.1 X - 1 9

5X = 5.1 X -1.9
5.1X - 5X = 1.9
0.1X = 1.9
X = 19

jadi jmlah siswa semula 19 orang :)
semoga bermanfaat :)