ÌâÄ¿ÄÚÈÝ
£¨2012•¶õÖÝ£©Ä³Ë½Óª·þ×°³§¸ù¾Ý2011ÄêÊг¡·ÖÎö£¬¾ö¶¨2012Äêµ÷Õû·þ×°ÖÆ×÷·½°¸£¬×¼±¸Ã¿ÖÜ£¨°´120¹¤Ê±¼ÆË㣩ÖÆ×÷Î÷·þ¡¢ÐÝÏзþ¡¢³ÄÒ¹²360¼þ£¬ÇÒ³ÄÒÂÖÁÉÙ60¼þ£®ÒÑ֪ÿ¼þ·þ×°µÄÊÕÈëºÍËùÐ蹤ʱÈçÏÂ±í£º
ÉèÿÖÜÖÆ×÷Î÷·þx¼þ£¬ÐÝÏзþy¼þ£¬³ÄÒÂz¼þ£®
£¨1£©ÇëÄã·Ö±ð´Ó¼þÊýºÍ¹¤Ê±ÊýÁ½¸ö·½ÃæÓú¬ÓÐx£¬yµÄ´úÊýʽ±íʾ³ÄÒµļþÊýz£®
£¨2£©ÇóyÓëxÖ®¼äµÄº¯Êý¹Øϵʽ£®
£¨3£©ÎÊÿÖÜÖÆ×÷Î÷·þ¡¢ÐÝÏзþ¡¢³ÄÒ¸÷¶àÉÙ¼þʱ£¬²ÅÄÜʹ×ÜÊÕÈë×î¸ß£¿×î¸ß×ÜÊÕÈëÊǶàÉÙ£¿
·þ×°Ãû³Æ | Î÷·þ | ÐÝÏзþ | ³ÄÒ | ||||||
¹¤Ê±/¼þ |
|
|
| ||||||
ÊÕÈ루°ÙÔª£©/¼þ | 3 | 2 | 1 |
£¨1£©ÇëÄã·Ö±ð´Ó¼þÊýºÍ¹¤Ê±ÊýÁ½¸ö·½ÃæÓú¬ÓÐx£¬yµÄ´úÊýʽ±íʾ³ÄÒµļþÊýz£®
£¨2£©ÇóyÓëxÖ®¼äµÄº¯Êý¹Øϵʽ£®
£¨3£©ÎÊÿÖÜÖÆ×÷Î÷·þ¡¢ÐÝÏзþ¡¢³ÄÒ¸÷¶àÉÙ¼þʱ£¬²ÅÄÜʹ×ÜÊÕÈë×î¸ß£¿×î¸ß×ÜÊÕÈëÊǶàÉÙ£¿
·ÖÎö£º£¨1£©¸ù¾ÝÖÆ×÷Î÷·þ¡¢ÐÝÏзþ¡¢³ÄÒ¹²360¼þ£¬¼´¿ÉÁгöµÚÒ»¸öʽ×Ó£¬¸ù¾ÝÖÆ×÷Î÷·þÿ¼þ
¹¤Ê±£¬ÐÝÏзþÿ¼þÐè
¹¤Ê±£¬³ÄÒÂÿ¼þÐè
¹¤Ê±£¬¼´¿ÉÁгöµÚ¶þ¸öʽ×Ó£»
£¨2£©¸ù¾ÝÌâÒâµÃ³ö·½³Ì×éx+y+z=360ºÍ
x+
y+
z=120£¬ÓÃÏûÔª·¨°ÑzÏûÈ¥£¬¼´¿ÉµÃ³öyÓëxµÄº¯Êý¹Øϵʽ£»
£¨3£©¸ù¾ÝÖÆ×÷Ò»¼þÎ÷·þÊÕÈë3°ÙÔª£¬ÖÆ×÷Ò»¼þÐÝÏзþÊÕÈë2°ÙÔª£¬ÖÆ×÷Ò»¼þ³ÄÒÂÊÕÈë1°ÙÔª£¬µÃ³öa=3x+2y+1¡Áz£¬°Ñy=360-3x´úÈëÇó³ö¼´¿É£®
1 |
2 |
1 |
3 |
1 |
4 |
£¨2£©¸ù¾ÝÌâÒâµÃ³ö·½³Ì×éx+y+z=360ºÍ
1 |
2 |
1 |
3 |
1 |
4 |
£¨3£©¸ù¾ÝÖÆ×÷Ò»¼þÎ÷·þÊÕÈë3°ÙÔª£¬ÖÆ×÷Ò»¼þÐÝÏзþÊÕÈë2°ÙÔª£¬ÖÆ×÷Ò»¼þ³ÄÒÂÊÕÈë1°ÙÔª£¬µÃ³öa=3x+2y+1¡Áz£¬°Ñy=360-3x´úÈëÇó³ö¼´¿É£®
½â´ð£º£¨1£©½â£ºº¬ÓÐx£¬yµÄ´úÊýʽ±íʾ³ÄÒµļþÊýzΪ£º¢Ùz=360-x-y£¬¢Úz=£¨120-
x-
y£©¡Â
£¬¼´z=480-2x-
y£»
£¨2£©½â£º¸ù¾ÝÌâÒâµÃ£º
£¬
¡ß¢Ù¡Á3µÃ£º3x+3y+3z=1080¢Û£¬
¢Ú¡Á12µÃ£º6x+4y+3z=1440¢Ü£¬
¢Ü-¢ÛµÃ£º3x+y=360
¼´y=360-3x£¬
¡àyÓëxÖ®¼äµÄº¯Êý¹ØϵʽÊÇy=360-3x£»
£¨3£©½â£ºÉè×ÜÊÕÈëÊÇa°ÙÔª£¬
Ôòa=3x+2y+1¡Áz=3x+2£¨360-3x£©+1¡Á£¨120-
x-
y£©¡Â
£¬
°Ñy=360-3x´úÈëºóÕûÀíµÃ£º
a=720-x£¬
¡ßk=-1£¼0£¬aËæxµÄÔö´ó¶ø¼õÉÙ£¬
¡àµ±xÈ¡×îСֵʱ£¬aµÄÖµ×î´ó£¬
ÓÉÌâÒâµÃ£º
£¬
½âµÃ£º120¡Ýx¡Ý30£¬
¼´xµÄ×îСֵʱ30£¬
µ±x=30ʱ£¬y=360-3x=270£¬z=360-30-270=60£¬
×î¸ß×ÜÊÕÈëÊÇ£ºa=720-30=690£¬
´ð£ºÃ¿ÖÜÖÆ×÷Î÷·þ¡¢ÐÝÏзþ¡¢³ÄÒ·ֱðÖÆ30¼þ¡¢270¼þ¡¢60¼þʱ£¬²ÅÄÜʹ×ÜÊÕÈë×î¸ß£¬×î¸ß×ÜÊÕÈëÊÇ690°ÙÔª£®
1 |
2 |
1 |
3 |
1 |
4 |
4 |
3 |
£¨2£©½â£º¸ù¾ÝÌâÒâµÃ£º
|
¡ß¢Ù¡Á3µÃ£º3x+3y+3z=1080¢Û£¬
¢Ú¡Á12µÃ£º6x+4y+3z=1440¢Ü£¬
¢Ü-¢ÛµÃ£º3x+y=360
¼´y=360-3x£¬
¡àyÓëxÖ®¼äµÄº¯Êý¹ØϵʽÊÇy=360-3x£»
£¨3£©½â£ºÉè×ÜÊÕÈëÊÇa°ÙÔª£¬
Ôòa=3x+2y+1¡Áz=3x+2£¨360-3x£©+1¡Á£¨120-
1 |
2 |
1 |
3 |
1 |
4 |
°Ñy=360-3x´úÈëºóÕûÀíµÃ£º
a=720-x£¬
¡ßk=-1£¼0£¬aËæxµÄÔö´ó¶ø¼õÉÙ£¬
¡àµ±xÈ¡×îСֵʱ£¬aµÄÖµ×î´ó£¬
ÓÉÌâÒâµÃ£º
|
½âµÃ£º120¡Ýx¡Ý30£¬
¼´xµÄ×îСֵʱ30£¬
µ±x=30ʱ£¬y=360-3x=270£¬z=360-30-270=60£¬
×î¸ß×ÜÊÕÈëÊÇ£ºa=720-30=690£¬
´ð£ºÃ¿ÖÜÖÆ×÷Î÷·þ¡¢ÐÝÏзþ¡¢³ÄÒ·ֱðÖÆ30¼þ¡¢270¼þ¡¢60¼þʱ£¬²ÅÄÜʹ×ÜÊÕÈë×î¸ß£¬×î¸ß×ÜÊÕÈëÊÇ690°ÙÔª£®
µãÆÀ£º±¾Ì⿼²éÁËÒ»´Îº¯ÊýµÄÓ¦Ó㬽â´ËÌâµÄ¹Ø¼üÊÇÄÜ°ÑÓïÑÔת»¯³ÉÊýѧʽ×ÓÀ´±í´ï£¬ÌâÄ¿±È½ÏºÃ£¬µ«ÓÐÒ»¶¨µÄÄѶȣ®

Á·Ï°²áϵÁдð°¸
Ïà¹ØÌâÄ¿