Jawabanmu

2014-06-06T06:36:34+07:00
56 = nilai 10siswa /10
n10= 560

57= (560+ n5)15
n5 = 295

maka rata2 n5 = 59
2014-06-06T06:40:51+07:00
57 =X1.n1+X2.n2/n1+n2 = 56.10 + x2.5/10 + 5
57 = 560 + 5x/15
57.15 = 560 + 5X
855 = 560 + 5X
855-560 = 5X
295 = 5X
X = 295/5 = 59