1/10+1/40+1/88+...+1/460要怎样简算

问题描述:

1/10+1/40+1/88+...+1/460要怎样简算

原式=1/2*5+1/5*8+1/8*11+...1/20*23
=(1/2-1/5)/3+(1/5-1/8)/3+...+(1/20-1/23)/3
=(1/2-1/23)/3
=7/46