^2·^3-^5

5· 2· 3· 谢谢. 1 2 3 4 ·····7 ·······10 ········?1 3 5 7 ·····?······?··········290 1 4 9 ·····?······?··········? ^2·^3-^5 1+2+3+4+5····+50 证明1·3·5·····(2n-1)/2·4·6·····2n 变态数学题·······方程一道············x+2y+3z=1x=y+12x+3y+5z=2方程组············要过程············我解了之后总觉得无解····· 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 有5分和2分硬币共80枚共值2元3角2分其中5分硬币有多少枚快啊··············急·················很急啊 序列 1 2 3 4 5 6 ······ n 对应的数 1 3 6 10 21······? 计算1-2+3-4+5-6+······+99-100= 计算：(2+4+6+8+···+100)-(1+3+5+···+99) 1+2+3+4+5+6······38+39=? 计算1-2+3-4+5-6+······-98+99= 1+2+3+4+5······+100+101=几 1+2+3+4+5+······+9999=（ ） 急用 1+2+3+4+5+6· · · · · ·+2013等于多少 1*2*3*4*5*6*······*n的规律 1+2+3+4+5+······+1000＝?