Question

4£®½ñÄê˫ʮһ¶Ì¶ÌµÄ¼¸¸öСʱÄÚÏúÊÛ¶îÒѾ­´ïµ½ÁË1200ÒÚÈËÃñ±Ò£®Ðí¶àÉ̼Ҷ¼»áÀûÓÃÕâ¸öÆõ»ú½øÐдòÕÛ´ÙÏú»î¶¯£®¼×Âô¼ÒµÄAÉÌÆ·³É±¾Îª500Ôª£¬ÔÚ±ê¼Û800ÔªµÄ»ù´¡ÉÏ´ò9ÕÛÏúÊÛ£®
£¨1£©ÏÖÔÚ¼×Âô¼ÒÓû¼ÌÐø½µ¼ÛÎüÒýÂòÖ÷£¬ÎÊ×î¶à½µ¼Û¶àÉÙÔª£¬²ÅÄÜʹÀûÈóÂʲ»µÍÓÚ10%£¿
£¨2£©¾ÝýÌ屬ÁÏ£¬ÓÐһЩÂô¼ÒÏÈÌá¸ßÉÌÆ·¼Û¸ñºóÔÙ½µ¼Û´ÙÏú£¬´æÔÚÆÛÕ©ÐÐΪ£®ÒÒÂô¼ÒÒ²ÏúÊÛAÉÌÆ·£¬³É±¾¡¢±ê¼ÛÓë¼×Âô¼ÒÒ»Ö£¬ÒÔǰÿÖÜ¿ÉÊÛ³ö50¼þ£¬ÎªÀ©´óÏúÁ¿£¬¾¡¿ì¼õÉÙ¿â´æ£¬Ëû¾ö¶¨´òÕÛ´ÙÏú£®µ«ËûÏȽ«±ê¼ÛÌá¸ß3m%£¬ÔÙ´ó·ù½µ¼Û26mÔª£¬Ê¹µÃAÉÌÆ·ÔÚ˫ʮһµ±ÌìÂô³öµÄÊýÁ¿¾Í±ÈÔ­À´Ò»ÖÜÂô³öµÄÊýÁ¿Ôö¼ÓÁË$\frac{12}{5}$m%£¬ÕâÑùÒ»ÌìµÄÀûÈó´ïµ½ÁË20000Ôª£¬Çóm£®

Answer 1

·ÖÎö £¨1£©Éè½µ¼ÛxÔª£¬¸ù¾Ý¡°ÀûÈóÂʲ»µÍÓÚ10%¡±Áгö²»µÈʽÇó½â¼´¿É£»
£¨2£©Éèm%=a£¬¸ù¾Ý¡°AÉÌÆ·ÔÚ3ÔÂ15ÈÕÄÇÒ»ÌìÂô³öµÄÊýÁ¿¾Í±ÈÔ­À´Ò»ÖÜÂô³öµÄÊýÁ¿Ôö¼ÓÁË$\frac{12}{5}$m%£¬ÕâÑùÒ»ÌìµÄÀûÈó´ïµ½ÁË20000Ôª¡±Áгö·½³ÌÇóµÃaºó¼´¿ÉÇóµÃmµÄÖµ£®

½â´ð ½â£º£¨1£©Éè½µ¼ÛxÔª£¬Áв»µÈʽΪ£¨800¡Á0.9-x£©¡Ý500£¨1+10%£©£¬
½âµÃ£ºx¡Ü170£¬
´ð£ºÎÊ×î¶à½µ¼Û170Ôª£¬²ÅÄÜʹÀûÈóÂʲ»µÍÓÚ10%£»

£¨2£©Éèm%=a£¬¸ù¾ÝÌâÒâµÃ£º[800£¨1+3a£©-2600a-500]•50£¨1+$\frac{12}{5}$a£©=20000£¬
ÕûÀíµÃ£º24a²-26a+5=0£¬
½âµÃ£ºa₁=$\frac{5}{6}$£¬a₂=$\frac{1}{4}$£¨ÉáÈ¥£©£¬
¡àm%=$\frac{5}{6}$£¬
¡àm=$\frac{250}{3}$£®

µãÆÀ ±¾Ì⿼²éÁËÒ»Ôª¶þ´Î·½³ÌµÄÓ¦Óü°Ò»ÔªÒ»´Î²»µÈʽµÄÓ¦Ó㬽âÌâµÄ¹Ø¼üÊÇ´ÓÌâÄ¿ÖÐÕûÀí³öµÈÁ¿¹ØϵºÍ²»µÈ¹Øϵ£¬ÄѶȲ»´ó£®