1.2/(1*3)+2/(3*5)+2/(5*7)+2/(9*11)
来源:学生作业帮 编辑:神马作文网作业帮 分类:数学作业 时间:2024/09/25 04:24:43
1.2/(1*3)+2/(3*5)+2/(5*7)+2/(9*11)
2.1/(1*3)+1/(3*5)+1/(5*7)+……+1/(97*99)
3.1-(5/6)+(7/12)-(9/20)+(11/30)-(13/42)+(15/56)-(17/72)+(79/90)
4.(88888888*88888888)/(1+2+3+4+5+6+7+8+7+6+5+4+3+2+1)
5.(1234+4567*7890)/4568*7890-6656
建议先在纸上列出式子,如果这样看会感觉很混乱,荣誉出错哦
2.1/(1*3)+1/(3*5)+1/(5*7)+……+1/(97*99)
3.1-(5/6)+(7/12)-(9/20)+(11/30)-(13/42)+(15/56)-(17/72)+(79/90)
4.(88888888*88888888)/(1+2+3+4+5+6+7+8+7+6+5+4+3+2+1)
5.(1234+4567*7890)/4568*7890-6656
建议先在纸上列出式子,如果这样看会感觉很混乱,荣誉出错哦
1.2/(1*3)+2/(3*5)+2/(5*7)+……+2/(9*11)
=1-1/3+1/3-1/5+1/5-1/7+……+1/9-1/11
=1-1/11
=10/11
2. 1/(1*3)+1/(3*5)+1/(5*7)+……+1/(97*99)
= 1/2[1-1/3+1/3-1/5+1/5-1/7+……+1/97/-1/99]
= 1/2[1-1/99]
=1/2*98/99
=49/99
3.1-(5/6)+(7/12)-(9/20)+(11/30)-(13/42)+(15/56)-(17/72)+(19/90)
=1-(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)+(1/9+1/10)
=1/2+1/10
=6/10
=3/5
4.(88888888*88888888)/(1+2+3+4+5+6+7+8+7+6+5+4+3+2+1)
=(11111111*8)^2/[(1+7)*7+8]
=111111111^2*8^2/8^2
=11111111^2
=1-1/3+1/3-1/5+1/5-1/7+……+1/9-1/11
=1-1/11
=10/11
2. 1/(1*3)+1/(3*5)+1/(5*7)+……+1/(97*99)
= 1/2[1-1/3+1/3-1/5+1/5-1/7+……+1/97/-1/99]
= 1/2[1-1/99]
=1/2*98/99
=49/99
3.1-(5/6)+(7/12)-(9/20)+(11/30)-(13/42)+(15/56)-(17/72)+(19/90)
=1-(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)+(1/9+1/10)
=1/2+1/10
=6/10
=3/5
4.(88888888*88888888)/(1+2+3+4+5+6+7+8+7+6+5+4+3+2+1)
=(11111111*8)^2/[(1+7)*7+8]
=111111111^2*8^2/8^2
=11111111^2
计算:2/3*5+1/5*7+1/7*9+1/9*11+1/11*13
1+3+5+7+9+11+--------+2n-1=?
观察下面一组数:-1/2,3/2,-5/2,7/2,-9/2,11/2
(3/5+6/7+9/11)÷(2/7+1/5+3/11)
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