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已知等差数列{an}的前n项和为Sn,且a3=5,S15=225.(Ⅰ)求数列{an}的通...
试题详情
已知等差数列{a
n}的前n项和为S
n,且a
3=5,S
15=225.
(Ⅰ)求数列{a
n}的通项公式;
(Ⅱ)设
![](data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAFQAAAAnCAYAAACR3W+uAAAAAXNSR0IArs4c6QAAAARnQU1BAACx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)
,求数列{b
n}的前n项和T
n.
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已知等差数列{an}的前n项和为Sn,且a3=5,S15=225;等比数列{bn}满足:b3=a2+a3,b2b5=128
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已知等差数列{an}的前n项和为Sn,且a3=5,S15=225.
(Ⅰ)求数列{an}的通项公式;
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