Jawabanmu

Jawaban paling cerdas!
2014-04-16T20:25:16+07:00
A. b=U2-U1
=(2x+2)-(2x+1)
=1
b. Un=a+(n-1)b
2x+50=(2x+1)+(n-1)1
2x+5=2x+n
2x-2x+50=n
n=50
c. Sn=n÷2(a+Un)
4275=50÷2(2x+1+2x+50)
4275=25(4x+51)
4275=100x+1275
4275-1275=100x
x=3000÷100
x=30
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