设数列{an}为等差数列,其前n项和为Sn,且S4=-62,S6=-75求|a1|+|a2|+……+

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Sn=a1n + n(n-1)d/2
S4=4a1+6d=-62
S6=6a1+15d=-75
a1=-20,d=3
an=a1+(n-1)d=3n-23
当n＜8时,an＜0
当n≥8时,an＞0
∴|a1|+|a2|+……+|a14|
= -(a1+a2+a3+a4+a5+a6+a7) +a8+a9+a10+a11+a12+a13+a14
= -S7+(S14-S7)
= -2S7+S14
= -2×(-77)-7
=147