123+246+369+.102030

精选知识

=[1*2*3*4*(1 3^4 5^4)]/[3*4*5*6*(1 3^4 5^4)] =(1*2*3*4)/(3*4*5*6) =2/30 =1/15 提取,约分 提取公因式

其他类似问题

问题1：1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,30,40,50,60,70,80,90,的英语咋写[英语科目]

one, two, three, four, five, six, seven, eight, nine, ten,

eleven, twelve, thirteen, fourteen, fifteen, sixteen, seventeen, eighteen, nineteen,

twenty, thirty, forty, fifty, sixty, seventy, eighty, ninety

注意40的写法就可以了

问题2：1+2+3+4+5+6+7+8+9+10+20+30+40+50.+100

5050

问题3：1又1/2+2又1/6+3又1/12+4又1/20+5又1/30+6又1/42+7又1/56+8又1/72+9又1/90+10又1/110[数学科目]

56

问题4：用英语表示时间 1:30 2:20 3:40 4:45 5:15 6:48 7:59 8:55 9:45 10:10 11:47 12:00

half past one

two twenty (twenty after two)

three fourty (twenty to four)

four forty-five (a quarter to five)

a quarter past five

six forty-eight

one to eight

five to nine

a quarter to ten (eight fifty-five)

ten past ten

eleven forty-seven

twelve o'clock

问题5：1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,30,40,50,60,70,80,90,的序数词英语咋写[英语科目]

（1）从第一至第十九 其中,one— first,two— second,three— third,five— fifth,eight—eighth,nine—ninth,twelve— twelfth为特殊形式,其它的序数词都是由其相对应的基数词后面添加“th”构成.例如：six— sixth、nineteen— nineteenth．

（2）从第二十至第九十九 整数第几十的形式由其对应的基数词改变结尾字母y为i,再加“eth”构成.

twenty——twentieth thirty——thirtieth

表示第几十几时,用几十的基数词形式加上连字符“－”和个位序数词形式一起表示.thirty-first 第三十一 fifty-sixth 第五十六 seventy-third 第七十三 ninety-ninth 第九十九