Question

1+2+3+4+5+6+7+8+9+8+7+6+5+4+3+2+1/88888888乘以88888888的简便方法怎么做

Answer 1

（1+2+3+4+5+6+7+8+7+6+5+4+3+2+1）/(88888888*88888888) =8*8/(88888888*88888888) =1/(1111111*1111111)=1/123456787654321 =[(1+7)+(2+6)+(3+5)+8+(7+1)+(6+2)+(5+3)+(4+4)]/(88888888*88888888) =8*8/(88888888*88888888) =1/(11111111*11111111) =1/123456787654321 （1+2+3+4+5+6+7+8+7+6+5+4+3+2+1）/(88888888*88888888) =8*8/(88888888*88888888) =1/(1111111*1111111)=1/123456787654321