(100+99-98-97+···+4+3-2-1)*(2012*2013-1)分之(2012+2011*2013)(2012+2011*2013)(100+99-98-97+···+4+3-2-1)*(2012*2013-1)*-----------------------------(2012*2013-1)(2012+2011*2013)-------------------------------(2012*2013-1)

巧算：100+99-98-97+96+95-·····+4+3-2-1 100+99-98-97+96+95+·······+4+3-2-1怎么做? 100-99+98-97+96-95+······+12-11+10=? 数学奥林匹克1-2+3-4+5-6+···+97-98+99+100=? 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·························· 8+11+14+17+20+·······+305 数学计算题.呜呜呜1+2+3+4+···················+98+99+100+99+98+···············+3+2+1 计算100-99+98-97+··+6-5+4-3+2-1=? 100·100-99·99+98·98-97·97+96·96-95·95+····+2·2-1·1的解题过程? 100²-99²+98²-97²+······+2²-1²=（ ) 100²-99²+98²-97²+96²-······-1² 怎么算 计算100²-99²+98²-97²+96²+··········+2²-1的值 计算题:1+2+(-3)+(-4)+5+6+(-7)+(-8)+···97+98+(-99)+(-100)怎么做? 1+2-3+4+5-6······+97+98-99的解题方法是巧算快 100+99-98+97-96+···+3-2+1=()要简便计算 1+3+5+···45+47+49+50+51+53+55+···+95+97+99-2-4-6-···-96-98-100＝ 1+2+3+······+95+96+97+98+99=? 计算1/（1*4）+1/（4*7）+1/（7*10)+------+1/(97*100)································································································ 帮忙算一道题 简便算法··100-99+98-97+96-...+4-3+2-1拜托啦