ÌâÄ¿ÄÚÈÝ
20£®Ö»ÁÐ×ÛºÏËãʽ£¬²»¼ÆË㣮£¨1£©¼×¡¢ÒÒÁ½¸öÖþ·¶ÓÒªÐÞÒ»Ìõ³¤95.3ǧÃ׵ū·£¬¼×¶ÓÿÌìÐÞ5.4ǧÃ×£¬ÒÒ¶ÓÿÌìÐÞ6.1ǧÃ×£®¼×¶ÓÏȹ¤×÷7Ì죬ÓàϵÄÁ½¶ÓºÏÐÞ£¬»¹ÐèÒª¶àÉÙÌìÍê³É£¿ÁÐʽ£º£¨95.3-5.4¡Á7£©¡Â£¨5.4+6.1£©
£¨2£©Ä³ÖÖÑÀ¸àÔ¼Û15ÔªÒ»ºÐ£¬ÎªÁË´ÙÏú£¬½µµÍÁ˼۸ñ£¬Òò´ËÏúÁ¿Ôö¼ÓÁË2±¶£¬ÊÕÈëÔö¼ÓÁË$\frac{3}{5}$£®ÎÊÒ»ºÐÑÀ¸à½µ¼Û¶àÉÙÔª£¿ÁÐʽ£º£¨15-x£©¡Á1¡Á£¨2+1£©=15¡Á£¨1+$\frac{3}{5}$£©
£¨3£©¼×¡¢ÒÒÁ½Á¾Æû³µ¶¼´Ó¼×µØ¿ªÍùÒҵأ¬¼×³µÃ¿Ð¡Ê±ÐÐ65ǧÃ×£¬ÒÒ³µÃ¿Ð¡Ê±ÐÐ42ǧÃ×£¬ÒÒ³µÏÈÐÐ2Сʱºó¼×³µÔÙ³ö·¢£¬ÔÙ¾¹ý¼¸Ð¡Ê±£¬¼×³µ³¬¹ýÒÒ³µ8ǧÃ×£¿ÁÐʽ£º£¨42¡Á2+8£©¡Â£¨65-42£©£®
·ÖÎö £¨1£©ÏÈÓü׶ÓÿÌìÐ޵ij¤¶È³ËÉÏ7Ì죬Çó³ö¼×¶ÓÒѾÐ޵ij¤¶È£¬ÔÙÓÃÈ«³¤¼õÈ¥¼×¶ÓÐ޵ij¤¶È£¬Çó³öʣϵij¤¶È£¬ÔÙÓÃʣϵij¤¶È³ýÒÔ¼×ÒҵŤ×÷ЧÂʺͼ´¿ÉÇó½â£»
£¨2£©±¾ÌâÔËÓ÷½³Ì½â´ð½ÏÈÝÒ×Àí½â£¬ÉèÏúÁ¿Êǵ¥Î»1£¬½µÁËxÔª£®ÏÖÔÚµÄÊÕÈë=ÔÀ´+±ÈÔÀ´Ôö¼ÓÁË$\frac{3}{5}$£¬ÓÉ´Ë¿ÉÒÔÇóµÃÒ»ºÐÑÀ¸à½µ¼ÛµÄÇ®Êý£»
£¨3£©¼×³µÃ¿Ð¡Ê±ÐÐ65ǧÃ×£¬ÒÒ³µÃ¿Ð¡Ê±ÐÐ42ǧÃ×£¬ÔòÁ½³µµÄËٶȲîÊÇÿСʱ65-42ǧÃ×£¬ÓÖÒÒ³µÏÈÐÐ2СʱºóÁ½³µÏà¾à42¡Á2ǧÃ×£¬µ±¼×³µ³¬¹ýÒÒ³µ8ǧÃ×ʱ£¬¼×³µ±ÈÒÒ³µ¶àÐÐ42¡Á2+8ǧÃ×£¬Ôò´Ëʱ¼×³µÐÐÁË£¨42¡Á2+8£©¡Â£¨65-42£©Ð¡Ê±£®
½â´ð ½â£º£¨1£©£¨95.3-5.4¡Á7£©¡Â£¨5.4+6.1£©
=£¨95.3-37.8£©¡Â11.5
=57.5¡Â11.5
=5£¨Ì죩
´ð£º»¹ÐèÒª5ÌìÍê³É£®
£¨2£©ÉèÏúÁ¿Êǵ¥Î»1£¬½µÁËxÔª£®
ÔÀ´µÄÊÕÈëÊÇ£º1¡Á15=15Ôª£¬
ÏÖÔÚµÄÊÕÈëÊÇ£º£¨15-x£©¡Á1¡Á£¨2+1£©=45-3x
45-3x=15¡Á£¨1+$\frac{3}{5}$£©
45-3x=24
45-3x+3x-24=3x+24-24
3x=21
3x¡Â3=21¡Â3
x=7£»
´ð£ºÒ»ºÐÑÀ¸à½µ¼Û7Ôª£®
£¨3£©£¨42¡Á2+8£©¡Â£¨65-42£©
=£¨84+8£©¡Â23
=92¡Â23
=4£¨Ð¡Ê±£©£®
´ð£ºÔÙ¾¹ý4Сʱ£¬¼×³µ³¬¹ýÒÒ³µ8ǧÃ×£®
¹Ê´ð°¸Îª£º£¨95.3-5.4¡Á7£©¡Â£¨5.4+6.1£©£¬£¨15-x£©¡Á1¡Á£¨2+1£©=15¡Á£¨1+$\frac{3}{5}$£©£¬£¨42¡Á2+8£©¡Â£¨65-42£©£®
µãÆÀ ½â¾öʵ¼ÊÎÊÌ⣬ÏȰÑʵ¼ÊÎÊÌâת»¯³ÉÊýѧÎÊÌ⣬ÔÙ¸ù¾ÝÊýÁ¿¹ØÏµÁÐʽÇó½â£®
| A£® | 6 | B£® | 11 | C£® | 4 | D£® | 12 |