Jawabanmu

2014-04-23T18:47:22+07:00
(6 + x + 3 +6 +7 + 7 + 6 + x + 8) / 10= 6.8
(58 + 2x ) / 10 = 6,8
58 + 2x = 68
2x = 68-58
2x = 10
x = 5