1/2 + 1/6 + 1/12 + 1/20 + 1/30+ 1/42 + 1/56 + 1/72=
来源:学生作业帮 编辑:大师作文网作业帮 分类:数学作业 时间:2024/09/29 22:24:20
1/2 + 1/6 + 1/12 + 1/20 + 1/30+ 1/42 + 1/56 + 1/72=
(1+ 1/2+ 1/3+ 1/4+ 1/5)×(1/2+ 1/3+ 1/4+ 1/5+ 1/6)-(1+ 1/2+ 1/3+ 1/4+1/5+ 1/6)×(1/2+ 1/3+ 1/4+ 1/5)
(1+ 1/2+ 1/3+ 1/4+ 1/5)×(1/2+ 1/3+ 1/4+ 1/5+ 1/6)-(1+ 1/2+ 1/3+ 1/4+1/5+ 1/6)×(1/2+ 1/3+ 1/4+ 1/5)
1/2 + 1/6 + 1/12 + 1/20 + 1/30+ 1/42 + 1/56 + 1/72
=(1-1/2)+(1/2-1/3)+(1/3-1/4)+(1/4-1/5) +(1/5-1/6)+(1/6-1/7)+(1/7-1/8)+(1/8-1/9)
=1-1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6+1/6-1/7+1/7-1/8+1/8-1/9
=1-1/9
=8/9
(1+ 1/2+ 1/3+ 1/4+ 1/5)×(1/2+ 1/3+ 1/4+ 1/5+ 1/6)-(1+ 1/2+ 1/3+ 1/4+1/5+ 1/6)×(1/2+ 1/3+ 1/4+ 1/5)
=(1+1/2+1/3+1/4+1/5)×[(1/2+1/3+1/4+1/5)+1/6]-[(1+1/2+1/3+1/4+1/5)+1/6]×(1/2+1/3+1/4+1/5)
=(1+1/2+1/3+1/4+1/5)×(1/2+1/3+1/4+1/5)+(1+1/2+1/3+1/4+1/5)×1/6-(1+1/2+1/3+1/4+1/5)×(1/2+1/3+1/4+1/5)-(1/2+1/3+1/4+1/5)×1/6
=(1+1/2+1/3+1/4+1/5)×1/6-(1/2+1/3+1/4+1/5)×1/6
=(1+1/2+1/3+1/4+1/5-1/2-1/3-1/4-1/5)×1/6
=1×1/6
=1/6
=(1-1/2)+(1/2-1/3)+(1/3-1/4)+(1/4-1/5) +(1/5-1/6)+(1/6-1/7)+(1/7-1/8)+(1/8-1/9)
=1-1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6+1/6-1/7+1/7-1/8+1/8-1/9
=1-1/9
=8/9
(1+ 1/2+ 1/3+ 1/4+ 1/5)×(1/2+ 1/3+ 1/4+ 1/5+ 1/6)-(1+ 1/2+ 1/3+ 1/4+1/5+ 1/6)×(1/2+ 1/3+ 1/4+ 1/5)
=(1+1/2+1/3+1/4+1/5)×[(1/2+1/3+1/4+1/5)+1/6]-[(1+1/2+1/3+1/4+1/5)+1/6]×(1/2+1/3+1/4+1/5)
=(1+1/2+1/3+1/4+1/5)×(1/2+1/3+1/4+1/5)+(1+1/2+1/3+1/4+1/5)×1/6-(1+1/2+1/3+1/4+1/5)×(1/2+1/3+1/4+1/5)-(1/2+1/3+1/4+1/5)×1/6
=(1+1/2+1/3+1/4+1/5)×1/6-(1/2+1/3+1/4+1/5)×1/6
=(1+1/2+1/3+1/4+1/5-1/2-1/3-1/4-1/5)×1/6
=1×1/6
=1/6
1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72
1/2 + 1/6 + 1/12 + 1/20 + 1/30+ 1/42 + 1/56 + 1/72=
1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90+.1/9900
1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90+1/10
1-(1/2)+(1/6)+(1/12)+(1/20)+(1/30)+(1/42)+(1/56)+(1/72)+(1/9
1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90+1/110
谁能巧算1-1/2-1/6-1/12-1/20-1/30-1/42-1/56-1/72-1/90
2/1+6/1+12/1+20/1+30/1+42/1+56/1+72/1+90/1等于多少
1.计算:1 - 1/2 - 1/6- 1/12 - 1/20 - 1/30 - 1/42 - 1/56 - 1/72
2\1-6\1-12\1-20\1-30\1-42\1-56\1-72\1-90\1
1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+190+1/110=?
1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90