Jawabanmu

Jawaban paling cerdas!
2014-04-08T22:55:42+07:00
Itu trmasuk barisan aritmetika.. a2 - a1 = a3 - a2 -> (-p+9)-(2p+25) = (3p+7)-(-p+9) -> -3p - 16 = 4p -2 -> -7p = 14 shg p = -2.. nah a1 = 2(-2)+25 = 21.. a2 = -(-2)+9 = 11.. bedany 11-21 = -10.. S10 = 10/2(2.21 + 9.(-10) = 5.(42-90) = 5.(-48) = -240.. jdikan yg terbaik y :)
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