1/2+1/3+2/3+1/4+2/4+3/4+1/5+2/5+…+1/50+2/50+…+49/50=?

来源:学生作业帮助网 编辑:作业帮 时间:2024/03/29 23:43:02
1/2+1/3+2/3+1/4+2/4+3/4+1/5+2/5+…+1/50+2/50+…+49/50=?

1/2+1/3+2/3+1/4+2/4+3/4+1/5+2/5+…+1/50+2/50+…+49/50=?
1/2+1/3+2/3+1/4+2/4+3/4+1/5+2/5+…+1/50+2/50+…+49/50=?

1/2+1/3+2/3+1/4+2/4+3/4+1/5+2/5+…+1/50+2/50+…+49/50=?
1/2+1/3+2/3+1/4+2/4+3/4+1/5+2/5+3/5+4/5+~+48/50+49/50
=1/2+(1+2)/3+(1+2+3)/4+(1+2+3+4)/5+(1+2+3+4+5)/6+(1+2+3+4+5+6)/7
+(1+2+3+4+5+6+7)/8+(1+2+3+4+5+6+7+8)/9+(1+2+3+4+5+6+7+8+9)/10
=1/2+3/3+6/4+10/5+15/6+21/7+28/8+36/9+45/10
=1/2+1+3/2+2+5/2+3+7/2+4+9/2
=1+2+3+4+(1+3+5+7+9)/2
=10+25/2
=22+1/2