Question

“@”表示一种新的运算符号，已知：2@3=2+3+4:；7@2=7+8；3@5=3+4+5+6+7；按此规则，如果n@8=68，那么n=

要过程

Answer 1

n@8就是N开始的8个连续数字相加的和

n@8
= N + N + 1 + N + 2 + …… + N + 7
= 8N + (1 + 7)×7/2
= 8N + 28

Answer 2

5

Answer 3

N@8=N+N+1+N+2+N+3+N+4+N+5+N+6+N+7=8N+28
8N+28=68
N=5