2·6

3.5--6x=2x--8.7的x的值作业急啊······················································· 2·6 证明1·3·5·····(2n-1)/2·4·6·····2n 2,3,4,6,6,12········· 填数字 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 序列 1 2 3 4 5 6 ······ n 对应的数 1 3 6 10 21······? 2+4+6+····+2008+02102+4+6+····+2008+0210+ x^4+5x^2-6因式分解帮忙·············小女子先谢拉 人教版小学六年级数学上册12到13页的2,5,6,快············· 6·2×0·99用简算 6·8×2·56=2·56×[] 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=? 简算 1/2+1/6+1/12+······+1/9900 计算1-2+3-4+5-6+······-98+99= 2-4+6-8+······+2002-2004+2006= 等于几? 1+2+3+4+5+6· · · · · ·+2013等于多少