急！求过程！！

显示全部楼层 · 2007-10-7 15:51:11

原式=1-2*（1/2+1/5+1/8+1/41）=-573/820

千问 · 2007-10-7 15:51:11

-1/2-1/5-1/8+1/11-1/20-1/41+1/110+1/1640=-(1/2+1/5+1/8+1/11-1/20+1/41+1/110+1/1640)+2/11+2/110+2/1640=-1+2/11+2/110+2/1640=-110/110+20/110+2/110+1/820=(-110+20+2)/110+1/820=-88/110+1/840=(-88*84)/(110*84)+11/(840*11)=(-7392+11)/(110*84)=-7381/(84*110)=(-11*671)/(11*840)=-671/840.

千问 · 2007-10-7 15:51:11

-1/2-1/5-1/8+1/11-1/20-1/41+1/110+1/1640＝1－2×（1/2+1/5+1/8+1/41）=？

千问 · 2007-10-7 15:51:11

两边减去2*(1/2+1/5+1/8)结果是1-2*(1/2+1/5+1/8)=-11/20

千问 · 2007-10-7 15:51:11

按计算器令所求的式子等于x然后两个式子相加把能约去的约去动手算吧...