=1/5×（1+1/6+1/12+...+1/72）
=1/5×（1+1/2-1/3+1/3-1/4+1/4-1/5+...+1/8-1/9）
=1/5×（3/2-1/9）
=1/5×（27/18-2/18）
=1/5×25/18
=5/18本回答被提问者采纳
=1/5(1+1/2-1/3+…+1/8-1/9)
=1/5(1+1/2-1/9)
=5/18
1\/5+1\/30+1\/60+…+1\/360=?求步骤
1\/5+1\/30+1\/60+…+1\/360 =1\/5×（1+1\/6+1\/12+...+1\/72）=1\/5×（1+1\/2-1\/3+1\/3-1\/4+1\/4-1\/5+...+1\/8-1\/9）=1\/5×（3\/2-1\/9）=1\/5×（27\/18-2\/18）=1\/5×25\/18 =5\/18
1\/5+1\/30+1\/60+…+1\/360=
n×(n-2)×(n+2)=n3-4n 1×3×5+4×6×8+7×9×11+……+28×30×32 =33-12+63-24+93-36+……+303-120 =(33+63+93+...+303)-(12+24+36+……+120) =33×(13+23+33+...+103)-(12+120)×10÷2 =27×(1+2+3+...+10)2-615 =27×552-615 =27×3025-615 ...
五分之一加三十分之一加六十分之一加省略号加三百六十分之一用简便...
1\/5+1\/30+1\/60+...+1\/360 ＝1\/5×（1+1\/6+1\/12+...+1\/72）＝1\/5×（1+1\/2-1\/3+1\/3-1\/4+...+1\/8-1\/9）＝1\/5×（1+1\/2-1\/9）＝1\/5×（1+7\/18）＝1\/5×25\/18 ＝5\/18 ＝18分之5
将四分之一拆分成四个不同的,单位分数之和?
1\/5+1\/29+1\/65+1\/7540=1\/4 1\/5+1\/30+1\/61+1\/3660=1\/4 1\/5+1\/31+1\/60+1\/930=1\/4 1\/5+1\/32+1\/54+1\/4320=1\/4 1\/5+1\/33+1\/51+1\/11220=1\/4 1\/5+1\/34+1\/50+1\/1700=1\/4 1\/5+1\/35+1\/47+1\/6580=1\/4 1\/5+1\/36+1\/46+1\/2070=1\/4 1\/5+1\/37+1\/...
1\/3+8\/1+1\/15+...+1\/360等于多少
1\/360=1\/(18*20)=1\/2*(1\/18-1\/20)1\/3+1\/8+1\/15+1\/24+...+1\/360 =1\/2*[(1-1\/3)+(1\/2-1\/4)+(1\/3-1\/5)+...+(1\/17-1\/19)+(1\/18-1\/20)]=1\/2*(1+1\/2-1\/3+1\/3-1\/4+...-1\/17+1\/17-1\/18+1\/18-1\/19-1\/20)=1\/2*(1+1\/2-1\/19-1\/20)...
1+1\/3+1\/6+1\/10+1\/15+1\/21(要过程)
这样的题目没有真正的简算方法，只有先用短除法求出所有分母的最小公倍数作为公分母，即先通分再计算。1+1\/3+1\/6+1\/10+1\/15+1\/21 =210\/210+70\/210+35\/210+21\/210+14\/210+10\/210 =(210+70+35+21+14+10)\/210 =360\/210 =12\/7 ...
1\/3+1\/8+1\/15+1\/24+...+1\/360=
1\/360=1\/(18*20)=1\/2*(1\/18-1\/20)1\/3+1\/8+1\/15+1\/24+...+1\/360 =1\/2*[(1-1\/3)+(1\/2-1\/4)+(1\/3-1\/5)+...+(1\/17-1\/19)+(1\/18-1\/20)]=1\/2*(1+1\/2-1\/3+1\/3-1\/4+...-1\/17+1\/17-1\/18+1\/18-1\/19-1\/20)=1\/2*(1+1\/2-1\/19-1\/20)...
1\/8+1\/24+1\/48+1\/80+...+1\/360的答案是多少
1\/8+1\/24+1\/48+1\/80+...+1\/360 1\/(2x4)+1\/(4x6)+1\/(6x8)+…+1\/(18x20)=(1\/2)x[2\/(2x4)+2\/(4x6)+2\/(6x8)+…+2\/(18x20)]=(1\/2)x(1\/2-1\/4+1\/4-1\/6+1\/6-1\/8+…+1\/18-1\/20)=(1\/2)x(1\/2-1\/20)=9\/40 ...
1\/20+1\/30+1\/60=36\/360怎么计算出来的
通分 找20.30.60的最小公倍数是180，9\/180+6\/180+3\/180=18\/180 再把18\/180通分就是36\/360
1\/3+1\/8+1\/15+1\/24……+1\/320
1\/3+1\/8+1\/15+1\/24……+1\/360 =（1-1\/3+1\/2-1\/4+1\/3-1\/5+1\/4-1\/6+……+1\/18-1\/20）÷2 =（1+1\/2-1\/19-1\/20）÷2 =531\/380÷2 =531\/760
