书架上下两层共放有120本书，如果从上层拿15本到下层，测两层书架上的书同样多，上下两层原来各有多少本书
\u4e66\u67b6\u4e0a\u3001\u4e0b\u4e24\u5c42\u5171\u653e\u6709120\u672c\u4e66\u3002\u5982\u679c\u4ece\u4e0a\u5c42\u62ff15\u672c\u5230\u4e0b\u5c42\uff0c\u5219\u4e24\u5c42\u4e66\u67b6\u4e0a\u7684\u4e66\u540c\u6837\u591a\u3002\u4e0a\uff0c\u4e0b\u4e24\u5c42\u539f\u6765\u5404\u8bbe\u4e0a\u5c42x\u672c\uff0c\u5219\u4e0b\u5c42\u4e3a120-x\u672c\uff0c\u5219x-15=120-x+15\uff0c\u89e3\u5f97x=75\u672c\uff0c\u6240\u4ee5\u539f\u6765\u4e0a\u5c4275\u672c\uff0c\u4e0b\u5c4245\u672c\u3002
\u65b9\u6cd5\u4e00\uff1a\u4e0a\u5c42\uff1a\uff08120+15\u00d72\uff09\u00f72\uff0c=150\u00f72\uff0c=75\uff08\u672c\uff09\uff1b\u4e0b\u5c42\uff1a120-75=45\uff08\u672c\uff09\uff0e\u7b54\uff1a\u4e0a\u5c42\u539f\u6765\u6709\u4e6675\u672c\uff0c\u4e0b\u5c42\u539f\u6765\u6709\u4e6645\u672c\uff0e\u65b9\u6cd5\u4e8c\uff1a\u8bbe\u4e0a\u5c42\u539f\u6765\u6709\u4e66x\u672c\uff0c\u5219\u4e0b\u5c42\u539f\u6765\u6709\u4e66\uff08120-x\uff09\u672c\uff0c\u5f97x-15=120-x+15\uff0c 2x=150\uff0c x=75\uff08\u672c\uff09\uff1b\u5219120-x=120-75=45\uff08\u672c\uff09\uff0e\u7b54\uff1a\u4e0a\u5c42\u539f\u6765\u6709\u4e6675\u672c\uff0c\u4e0b\u5c42\u539f\u6765\u6709\u4e6645\u672c\uff0e
上层（120+15×2）÷2=150÷2
=75本
下层120-75=45本
设下层有a本书，则
a+a+15×2=120，得
a=45
所以下层有45本书，上层有45+15×2=75本书。
绛旓細鍜屽嶉棶棰 浠庣敳涔︽灦鍙栧嚭15鏈斁鍏ヤ箼涔︽灦锛杩欐椂鐢蹭功鏋剁殑涔︽槸涔欎功鏋剁殑3鍊嶏紝杩欐椂鎬诲拰涓嶅彉锛屽厛姹傚嚭杩欐椂鐨勭敳涔欎功鏋朵笂鏈暟 杩欐椂鐨勪箼=120梅锛3+1锛=30鏈紝鐢120-30=90鏈紝鍘熸潵鐨勭敳 90+15=105鏈
绛旓細璁句笂涓笅涓夊眰鍚勬斁x,y,z鏈功 鐢遍鍙緱锛1锛墄+y+z=120 (2)x-y=8 (3)y-z=2 鐢辨柟绋嬶紙2锛夊緱鍑(4)x=8+y,鐢辨柟绋嬶紙3锛夊緱鍑猴紙5锛墇=y-2 鎶婃柟绋嬶紙4锛夊拰锛5锛変唬鍏ユ柟绋嬶紙1锛夊緱鍑 锛8+y锛+y+(y-2)=120 3y=114 y=38 鎶妝=38鍒嗗埆浠ｅ叆鏂圭▼(3)鍜(4)寰楀嚭 x=46,z=36 鎵浠ヤ笂...
绛旓細120鏈功鍒嗕笁灞,姣灞備功鏈鏁扮洰涓鑷,灏辨槸40鏈竴灞.绗竴灞傛斁鍏13鏈埌绗浜屽眰,閭ｄ箞鍙互鎺ㄧ畻鍑虹浜屽眰鐨勪功鏁扮洰鏄40-13=27鏈紱绗竴灞傛斁鍏8鏈埌绗笁灞,鍙互鎺ㄧ畻鍑虹涓夊眰鐨勪功鏁扮洰鏄40-8=32锛涜繖鏍风涓灞傜殑涔︽暟鐩氨鏄40+13+8=61.
绛旓細120梅2/5=300鏈 鎬绘暟 300-120=180鏈 涓眰涓庝笅灞傛湰鏁板拰 180*4/(5+4)=80鏈
绛旓細2/(2+3)=40% [绠楀嚭鐢涔︽灦涓婄幇鍦ㄦ湁澶氬皯涔52%-40%=12% [绠楀嚭鎷胯蛋浜嗗灏慮120/12%=1000锛堟湰锛塠绠楀嚭杩欐壒涔﹀叡鏈夊灏戞湰]绛旓細杩欐壒涔﹀叡鏈1000鏈.瀵逛簬杩欑棰,鍙涓姝ヤ竴姝ユ潵,鎵句袱涓搴旂殑閲忓嵆鑳芥眰鍑烘婚噺.鍔犳补!
绛旓細1 (284-16+8)/(1+2+3)=46 46*3+16=154 46*2-8=842 (480+1240)/(1+3)=430 480-430=504 2304/(10-1)= 2304/(10-1)*10=5 (52*3-78)/2=39 78-39=39 52-39=13 6 (58+47+45)/2=75 75-58=17 75-48=28
绛旓細2+3=5 120*2/5=48(鏈)3-2=1 120*1/5+48=72(鏈)鏇寸畝鍗曚竴浜涘氨鏄細3+2=5
绛旓細X+120+17=200锛涳紙涓ょ櫨涓320-120,鍗崇涓灞備功鐨勬暟鐩級Y-17=200 绗簩姝ワ細寰楀嚭X=63锛沋=217锛涚涓夋锛氭墍浠ユ讳功鏁=320+63+217=600 鏈畬缁х画绗簩绉嶆柟娉 绗竴灞320鏈功鎷挎帀120鏈杩樻湁澶氬皯?缁撴灉鏄剧劧鏄200鏈,鐒跺悗鍛?棰樼洰璇翠笁鎴愪功鐨勬暟鐩竴鏍,閭ｄ箞鎰忔濇槸涓嶆槸闂綘杩欐牱涓涓棶棰樺憿?涔︽灦鍏辨湁涓夊眰涔,姣...
绛旓細涓眰鏈 锛120-8+2锛/3=38鏈 涓婂眰鏈38+8=46鏈 涓嬪眰鏈38-2=36鏈
绛旓細涓涓笁灞涔︽灦鍏辨斁涔120鏈涓婂眰姣斾腑灞傚8鏈笅灞傛瘮涓眰灏戞斁2鏈笂涓笅鍚勬斁澶氬皯鏈?涓眰锛120-8+2锛壝3 =114梅3 =38鏈 涓婂眰38+8=46鏈 涓嬪眰38-2=36鏈
