Jawabanmu

2014-05-16T13:23:06+07:00
B= 5X+2+X=6X+2
U2=a+(n-1)b
5X=2+X+6X+2
-2X=4
X=-2

U1=2+x=0
b=6X+2=-10

s8=n/2+ (2a+(n-1)b)
=4+(0-70)
=4

Maaf kalo salah..

Jawaban paling cerdas!
2014-05-16T13:24:11+07:00
2+x , 5x , x+14
syarat deret aritmatika, beda tetap
10x=2+x + x +14
x=2
S8 = 4(a+U8)
=4(4+46)
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