Jawab beserta Cara no 10

10. nilai rata2 5 anak = 6.4
nilai rata2 4 anak = 6
nilai anak yg keluar = ??
peny
6=[{5x6.4}-x]/4
6x4 =[{5x6.4}-x]
24= [ 32-x ]
x = 32+24
x= 56