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已知数列{an}、{bn}的前n项和分别为Sn、Tn,且Sn=2-2an,Tn=3-bn-...
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已知数列{a
n}、{b
n}的前n项和分别为S
n、T
n,且S
n=2-2a
n,T
n=3-b
n-
.
(I)求数列{a
n}、{b
n}的通项公式;
(II)求
(a
1b
1+a
2b
2+a
3b
3+…+a
nb
n).
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