2+5+8+14+······+101的简便计算,该怎么算啊?

来源:学生作业帮助网 编辑:作业帮 时间:2024/11/15 18:35:36

2+5+8+14+······+101的简便计算,该怎么算啊?
2+5+8+14+······+101的简便计算,该怎么算啊?

2+5+8+14+······+101的简便计算,该怎么算啊?
2 + 5 + 8 + 14 + …… + 101
= 2 + 5 + ( 2 + 5 + 1 ) + ( 5 + 8 + 1 ) + …… + 101
= 2 + 5 + 8 + 14 + ( 8 + 14 + 1 ) + ( 14 + 23 + 1 ) + ( 23 + 38 + 1 ) + ( 38 + 62 + 1 )
= 2 + 5 + 8 + 14 + 23 + 38 + 62 + 101
= 8 + 3 + 6 + 12 + 21 + 36 + 60 + 99 + 8
= 99 + ( 60 + 36 + 3 ) + ( 21 + 12 + 6 ) + 16
= 99 + 99 + 39 + 16
= 240 + 13
= 253

2+5+8+14+······+101的简便计算,该怎么算啊? 1的平方-2的平方+3的平方-4的平方+5的平方-6的平方+········+99的平方-100的平方+101的平方=? 俗语和名句的填空1······,自知之明.2······,行必果.3工欲善其事,······.4临渊羡鱼,······.5非学无以广才,······.6······,福兮祸之所伏.7项庄舞剑,······.8······,人以群 观察下列三角形数表其中从第二行起每行的每一个数为其肩膀上两树之和则该表的最后一个数是?1 2 3 4 5 6 7 8················ 97 98 99 100 3 5 7·························· 将下列每个3*3正方形内的九格以及横竖九格均填入一至九的数字,且不重复.· 8 9 · 2 ··1··· 1 ··· 3······· 6 7········· 8 2·········5 ···· 7 ··············· 9 8 ····7 · 一道高2数阵题12 34 5 67 8 9 1011 12 13 14 15······························根据以上排列规律,数阵中第n(n≥3)行的从左至右的第3个数是________ 求(2+5+8······+2000)-(1+4+7······+1999)的值.【简算】 全部属于裸子植物的是 1卷柏 2侧柏 3银杏 4刺槐 5苏铁 6梧桐 7云杉 8贯从 9珙桐 A1237 B2357 C2379 D1358贯从是贯众······························· 带有数字的四字词语按顺序1···2···3···4···5···6···7···8···9···10···祝福语 爱心公益广告的名言警句5分钟之内要的················· 带数字1·2·3·4·5·6·7·8·9·10·的成语,每个数字至少三个 若多项式x的平方加3x减5的值为2,求多项式2乘x平方加6x减3的值急····························· 一直关于x的方程为3x+a=5-6x1 有唯一的解2 3 有无数个解急································那么当a b 满足什么条件时 2的平方+4的平方+6的平方+8的平方+······+100的平方的值是多少?答案是171700, 求等差数列:-1,2,5,8,···的前10项的和? 0~100的素数的答案比如2·3·5·7·11·13······ 找出小正方形的个数与露在外面的数的变化规律小正方形的个数:1 2 3 4 ······( )······ n露在外面的面数:5 9 13 ( ) ······ 33 ······ ( ) 人教版小学六年级数学上册12到13页的2,5,6,快·············