问题
填空题
等比数列1，2，4…的前10项的和为______．
答案
根据题意，可得等比数列的首项为1，公比为
=2，2 1
则S10=
=210-1=1023；1(1-210) 1-2
故答案为1023．
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等比数列1，2，4…的前10项的和为______．
根据题意，可得等比数列的首项为1，公比为
=2，2 1
则S10=
=210-1=1023；1(1-210) 1-2
故答案为1023．
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