Respostas

2013-08-26T21:36:27-03:00
R=500
n=15
s=67500

an=a1+(n-1).r
an=a1+(15-1).500
an=a1+14.500
an=a1+7000>>

s=(a1+an).n/2
(a1+an)n=2s
(a1+a1+7000)15=2*67500
(2a1+7000)15=135000.........(:15)
2a1+7000=9000
2a1=9000-7000
2a1=2000
a1=1000>>

a3=a1+2.r
a3=1000+2.500
a3=1000+1000
a3=2000 metros no terceiro dia
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