1又3/10+3又3/40+5又3/88+7又3/154+9又3/238+11又3/340 拆分求值,麻烦说的详细点.

问题描述:

1又3/10+3又3/40+5又3/88+7又3/154+9又3/238+11又3/340 拆分求值,麻烦说的详细点.

1又3/10+3又3/40+5又3/88+7又3/154+9又3/238+11又3/340=(1+3+5+7+9+11)+(3/10+3/40+3/88+3/154+3/238+3/340 )=6×6+3×(1/10+1/40+1/88+1/154+1/238+1/340)=36+(1/2-1/5+1/5-1/8+1/8-1/11+1/11-1/14+1/14-1/1...=6×6+3×(1/10+1/40+1/88+1/154+1/238+1/340)这里的×3怎么到后来就没了呢?=36+(1/2-1/5+1/5-1/8+1/8-1/11+1/11-1/14+1/14-1/17+1/17-1/20)1/10=(1/2-1/5)/31/40=(1/5-1/8)/3…………………………1/340=(1/17-1/20)/3