a1.a2.a3.a100中任意三个相临之和都是37,已知a2=25,a9=2x,a99=3-x,那么a100=----

学习时间:2026-09-26 10:29:27 阅读：8952

a1.a2.a3.a100中任意三个相临之和都是37,已知a2=25,a9=2x,a99=3-x,那么a100=____________

靓丽的金鱼

2026-09-26 10:29:27

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即a1+a2+a3=37a2+a3+a4=37相减a1-a4=0a1=a4同理a1=a4=a7=a10=……=a100同样a3=a6=a9=……=a99所以2x=3-xx=1即a3=a9=2x=2a1+a2+a3=37a1=37-25-2=10所以a100=a1=10