An应该是32
An=A1+(n-1)d
n=(An-A1)/d+1
=(32-14.5)/0.7+1
=26
Sn=(A1+An)×n/2
=(14.5+32)×26/2
=604.5
等差数列:a1=14.5,d=0.7,an=3.2,求Sn...
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