每日一题：甲班有25人，乙班有75人，甲班和乙班的总平均分是90分。如果甲班的平均分比乙班的平均分

\u7532\u73ed\u670925\u4eba\uff0c\u4e59\u73ed\u670975\u4eba\uff0e\u7532\u73ed\u548c\u4e59\u73ed\u7684\u603b\u5e73\u5747\u5206\u662f90\u5206\uff0c\u5982\u679c\u7532\u73ed\u7684\u5e73\u5747\u5206\u6bd4\u4e59\u73ed\u7684\u5e73\u5747\u5206\u9ad85\u5206\uff0c\u90a3\u4e48\u4e59\u73ed

\u8bbe\u4e59\u73ed\u7684\u5e73\u5747\u5206\u662fx\u5206\uff0c\u7531\u9898\u610f\u5f97\uff1a75x+\uff08x+5\uff09\u00d725=90\u00d7\uff0825+75\uff09 100x+125=9000 100x+125-125=9000-125 100x=8875 100x\u00f7100=8875\u00f7100 x=88.75\u7b54\uff1a\u4e59\u73ed\u7684\u5e73\u5747\u5206\u662f88.75\u5206\uff0e

\u3000\u3000\u89e3\uff1a87\u00d7\uff0870+30\uff09=8700\u5206
\u3000\u30008700-90\u00d770=2400\u5206
\u3000\u30002400\u00f730=80\u5206
\u3000\u3000\u7b54\uff1a\u4e59\u73ed\u7684\u5e73\u5747\u5206\u6570\u662f80\u5206\u3002

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\u67f3\u6d6a\u95fb\u83ba\u5404\u4f4d\u829d\u9ebb\u7aed\u8bda\u4e3a\u60a8\u89e3\u7b54
\u60a8\u7684\u91c7\u7eb3\u662f\u6211\u4eec\u575a\u6301\u767e\u5ea6\u7684\u52a8\u529b
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甲乙两班总分为90×（25+75）=9000分，若甲班平均分和乙班同样多，则总分会减少为9000-25×5=8875分。乙班平均分为8875÷（25+75）=88.75分。

姣忔棩涓棰:鐢茬彮鏈25浜,涔欑彮鏈75浜,鐢茬彮鍜屼箼鐝殑鎬诲钩鍧囧垎鏄90鍒嗐傚鏋滅敳...
绛旓細鐢蹭箼涓ょ彮鎬诲垎涓90脳锛25+75锛=9000鍒嗭紝鑻鐢茬彮骞冲潎鍒嗗拰涔欑彮鍚屾牱澶氾紝鍒欐诲垎浼氬噺灏戜负9000-25脳5=8875鍒嗐備箼鐝钩鍧囧垎涓8875梅锛25+75锛=88.75鍒嗐

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