来自程怀济的问题
简便计算(要过程)1+19/6+61/12+141/20+271/30+463/421/1x4+1/4x7+1/7x10+.+1/73x76
简便计算(要过程)
1+19/6+61/12+141/20+271/30+463/42
1/1x4+1/4x7+1/7x10+.+1/73x76
1回答
2020-05-14 15:12
简便计算(要过程)1+19/6+61/12+141/20+271/30+463/421/1x4+1/4x7+1/7x10+.+1/73x76
简便计算(要过程)
1+19/6+61/12+141/20+271/30+463/42
1/1x4+1/4x7+1/7x10+.+1/73x76
(1)原式=1+3+5+7+9+11+1/2*3+1/3*4+1/4*5+1/5*6+1/6*7=12+12+12+1/2-1/3+1/3-1/4+1/5-1/6+1/6-1/7=36+1/2-1/7=36又5/14(2)1/1x4+1/4x7+1/7x10+...+1/73x76=1/3(1-1/4+1/4-1/7+...+1/73-1/76)=1/3*75/76=25/76...