Question

设一列数a1、a2、a3、···、a100中任意三个相邻数之和都是37,已知a2=25,a9=2x,a99=3-x,那么

Answer 1

an+a(n+1)+a(n+2)=37

a(n+1))+a(n+2))+a(n+3)=37

所以an=a(n+3)

a100=a1

2x=a9=a99=3-x => x=1

a3=a9=2x=2

a1=37-a2-a3=10

a100=10