£¨2£© µ×±ß³¤Îª a cm£¬¸ßΪ h cmµÄÈý½ÇÐεÄÃæ»ýÊÇ cm2£» £¨3£© ÀⳤΪ a cmµÄÕý·½ÌåµÄÌå»ýÊÇ cm3 £»
£¨4£©Ò»Ì¨µçÊÓ»úÔ¼Û a Ôª£¬ÏÖ°´Ô¼ÛµÄ9ÕÛ³öÊÛ£¬Õą̂µçÊÓ»úÏÖÔÚµÄÊÛ¼ÛÊÇ Ôª£»
£¨5£©Ò»¸ö³¤·½Ðεij¤ÊÇ0.9 m£¬¿íÊÇa m £¬Õâ¸ö³¤·½ÐεÄÃæ»ýÊÇ m2. ѧÉú»î¶¯£ºÏȶÀÁ¢Íê³É£¬ÔÙС×éºÏ×÷̽¾¿. ½Ìʦ×ܽ᣺
£¨1£©12n£¬ËüµÄϵÊýÊÇ12£¬´ÎÊýÊÇ1£»
11£¨2£©ah£¬ËüµÄϵÊýÊÇ£¬´ÎÊýÊÇ2£»
22£¨3£©a3£¬ËüµÄϵÊýÊÇ1£¬´ÎÊýÊÇ3£» £¨4£©0.9a£¬ËüµÄϵÊýÊÇ0.9£¬´ÎÊýÊÇ£±£» £¨5£©0.9a£¬ËüµÄϵÊýÊÇ0.9£¬´ÎÊýÊÇ1£®
ÄãÄܸ³Óè0.9aÒ»¸öº¬ÒåÂð£¿ÓÃ×Öĸ±íʾÊýºó£¬Í¬Ò»¸öʽ×Ó¿ÉÒÔ±íʾ²»Í¬µÄº¬Ò壮 ˼¿¼£º
Èô?m?2?x2ynÊǹØÓÚx¡¢y µÄÒ»¸öËĴε¥Ïîʽ£¬Çóm£¬nÓ¦Âú×ãµÄÌõ¼þ£¿ Èý¡¢¹®¹ÌÍØÕ¹
Á·Ï°£¨½Ì¿ÆÊéµÚ57Ò³Á·Ï°£© 1.Ìî±í µ¥Ïîʽ ϵÊý ´ÎÊý 2.Ìî¿Õ£º
£¨1£©.ȫУѧÉú×ÜÊýÊÇx£¬ÆäÖÐÅ®ÉúÕ¼48%£¬ÔòÅ®ÉúÈËÊýÊÇ £¬ÄÐÉúÈËÊýÊÇ £» £¨2£©Ò»Á¾³¤Í¾Æû³µ´ÓÑîÁø´å³ö·¢£¬3hºóµ½´ï¾à³ö·¢µØskmµÄϪºÓÕò£¬ÕâÁ¾³¤Í¾Æû³µµÄƽ¾ùËÙ
¶ÈÊÇ km/h£»
£¨3£©²úÁ¿³ömkgÔö³¤10%£¬¾Í´ïµ½ kg. ѧÉú»î¶¯£ºÏȶÀÁ¢Íê³É ½Ìʦ×ܽ᣺
2a2 ?1.2h xy2 ?t2 ?2vt 3
1. Ìî±í µ¥Ïîʽ ϵÊý ´ÎÊý 2.Ìî¿Õ
s£¨1£©0.48x¡¢0.52x£¨2£©£¨3£©1.1m£»
32a2 ?1.2h -1.2 1 xy2 1 3 ?t2 ?2 2 -1 2 2vt 32? 32 ËÄ¡¢¿ÎÌÃ×ܽá
£¨1£©±¾½Ú¿ÎѧÁËÄÄЩÖ÷ÒªÄÚÈÝ£¿
£¨2£©ÇëÄã¾ÙÀý˵Ã÷µ¥ÏîʽµÄ¸ÅÄî¡¢µ¥ÏîʽµÄϵÊýºÍ´ÎÊýµÄ¸ÅÄî. Îå¡¢×÷Òµ
½Ì¿ÆÊéµÚ59ҳϰÌâ2.1µÚ3Ìâ
°åÊéÉè¼Æ
1.µ¥Ïîʽ Àý3 µ¥ÏîʽµÄϵÊý µ¥ÏîʽµÄ´ÎÊý
2.1Õûʽ(µÚ3¿Îʱ)
½ÌѧĿ±ê£º
(1)Àí½â¶àÏîʽ¡¢¶àÏîʽµÄÏîºÍ´ÎÊý¡¢ÕûʽµÄ¸ÅÄ
(2)»á׼ȷÅж϶àÏîʽµÄÏî¡¢´ÎÊý£¬²¢¸ù¾Ý¶àÏîʽÖÐ×ÖĸµÄÖµÇó¶àÏîʽµÄÖµ£®
(3)¾ÀúÓÃÕûʽ±íʾÊýÁ¿¹ØϵµÄ¹ý³Ì£¬Ìå»áÓÃÕûʽ±íʾÊýÁ¿¹ØϵµÄ¼ò½àÐÔºÍÒ»°ãÐÔ£®
(4)ÅàÑøѧÉúµÄ¹Û²ì¡¢·ÝÎö¡¢¹éÄÉ¡¢³éÏó¸ÅÀ¨ÒÔ¼°ÓÃʽ×Ó±íʾÊýÁ¿¹ØϵµÄÒâʶºÍÄÜÁ¦. ½ÌѧÖص㣺
¶àÏîʽ¡¢¶àÏîʽµÄÏîºÍ´ÎÊýµÄ¸ÅÄÕûʽµÄ¸ÅÄî. ½ÌѧÄѵ㣺
¶àÏîʽµÄ´ÎÊý¸ÅÄîµÄÀí½â. ½Ì·¨£º»¥¶¯Ì½¾¿·¨ ѧ·¨£º С×éÑÐÌÖ·¨ ½Ìѧ¹ý³Ì£º ¸´Ï°
£¨1£©¶ÔÓÚµ¥Ïîʽ£¬ÎÒÃÇѧϰÁËÄÄЩÄÚÈÝ£¿
£¨2£©Çë¾ÙÀý˵Ã÷µ¥Ïîʽ¡¢µ¥ÏîʽµÄϵÊýºÍ´ÎÊýµÄ¸ÅÄ ѧÉú»î¶¯£ºÐ¡×éÌÖÂÛ ½Ìʦ½á£º
ѧϰÁËʲôÊǵ¥Ïîʽ¡¢µ¥ÏîʽµÄϵÊý¡¢µ¥Ïîʽ´ÎÊý£¬µ¥¶ÀµÄÒ»¸öÊý×ÖºÍ×ÖĸҲÊǵ¥Ïîʽ.
?¾ÙÀý£ºÈç?a2bc¡¢-1¡¢aµÈ.
2Ò»¡¢Çé¿öÒýÈë
ÎÊÌâ1£º¼¦ÍÃͬÁý£¬Óм¦aÖ»£¬ÍÃ×ÓbÖ»£¬ÄÇôÁý×ÓÀïÓм¸Ö»½Å£¿
ѧÉúºÏ×÷̽¾¿£ºÐ¡×éÌÖÂÛ¼¦¡¢Íø÷Óм¸Ö»½Å£¬ÓÃʽ×Ó±íʾÕâ¸öÊýÁ¿£¬È»ºóÏà¼Ó¼´µÃ½á¹û. ½Ìʦ×ܽ᣺Áý×ÓÀF¹²ÓÐ2aÖ»½Å£¬ÍÃ×Ó¹²ÓÐ4bÖ»½Å£¬ÄÇôÁý×ÓÀï¹²ÓÐ?2a?4b?Ö»½Å. ÕâÀïµÄʽ×Ó?2a?4b?ÊÇÎÒÃÇÒÔǰѧ¹ýµÄµ¥ÏîʽÂ𣿣¬ÏÔÈ»²»ÊÇ£¬ÕâÖÖʽ×Ó¾ÍÊÇÎÒÃǽñÌìҪѧϰµÄÐÂ֪ʶ.
1ÎÊÌâ2£ºÎÒÃÇÀ´¿´Àý2ÖеÄʽ×Ó£ºv?2.5£¬v?2.5£¬3x?5y?2z£¬ab??r2£¬x2?2x?18£¨1£©
2¹Û²ìʽ×ÓËüÃÇÓÐʲô¹²Í¬Ìص㣿Óëµ¥ÏîʽÓÐʲôÁªÏµ£¿ ѧÉú»î¶¯£ºÐ¡×éºÏ×÷̽¾¿
ʦÉúºÏ×÷̽¾¿£º¹Û²ìÿ¸öʽ×ÓÊÇ·ñ¶¼º¬Óе¥Ïîʽ£¬ÄãÄÜ˵³öËüÃÇÂð£¿
v?2.5¿ÉÒÔ¿´×÷µ¥ÏîʽvÓëµ¥Ïîʽ2.5µÄºÍ£¬v?2.5¿ÉÒÔ¿´×÷µ¥ÏîʽvÓëµ¥Ïîʽ2.5µÄ²î£¨»¹¿É
1ÒÔ¿´×÷ʲô£¿£©£¬3x?5y?2z¿ÉÒÔ¿´×÷µ¥Ïîʽ3x¡¢5yÓëµ¥Ïîʽ2zµÄºÍ£¬Í¬Ñùab??r2¿ÉÒÔ
21¿´×÷µ¥ÏîʽabÓëµ¥Ïîʽ?r2µÄ²î£¨»¹¿ÉÒÔ¿´×÷ʲô£¿£©£¬x2?2x?18¿ÉÒÔ¿´×÷
2x2¡¢2x¡¢18µÄºÍ.
ÏóÕâÑù£¬¼¸¸öµ¥ÏîʽµÄºÍ½Ð×ö¶àÏîʽ. ÿ¸öµ¥Ïîʽ½Ð×ö¶àÏîʽµÄÏ²»º¬×ÖĸµÄÏî½Ð×ö³£ÊýÏ ÀýÈ磬¶àÏîʽv?2.5µÄÏîÊÇvºÍ?2.5£¬ÆäÖÐ?2.5Êdz£ÊýÏÔÚ¶àÏîʽx2?2x?18ÖУ¬x2¡¢2x¡¢
18¾ÍÊÇËüµÄÏ18Êdz£ÊýÏî.
¶àÏîʽÀ´ÎÊý×î¸ßÏîµÄ´ÎÊý£¬½Ð×öÕâ¸ö¶àÏîʽµÄ´ÎÊý£®
Èç¶àÏîʽv?2.5ÖдÎÊý×î¸ßÏîÊÇÒ»´ÎÏîv£¬Õâ¸ö¶àÏîʽµÄ´ÎÊýÊÇ£±£»¶àÏîʽx2?2x?18ÖдÎÊý×î¸ßÏîÊǶþ´ÎÏîx2£¬Õâ¸ö¶àÏîʽµÄ´ÎÊýÊÇ£² µ¥ÏîʽÓë¶àÏîʽͳ³ÆÕûʽ£®
ÀýÈ磬µ¥Ïîʽ0.8p,mn,a2h,?n£¬ÒÔ¼°¶àÏîʽv?2.5¡¢v?2.5¡¢3x?5y?2z¡¢x2?2x?18µÈ¶¼ÊÇÕûʽ.
¶þ¡¢·¶Àýѧϰ Àý£º 2.5x?5 Õûʽ 6a2?1 ?2x3y2?x2?3 5a ?3x2y Ïî ´ÎÊý ϵÊý
ѧÉú»î¶¯£ºÀûÓöàÏîʽ¼°µ¥ÏîʽµÄ¸ÅÄî¶ÀÁ¢Íê³É£¬È»ºóС×éÌÖÂÛ´ð°¸. ʦÉúºÏ×÷£ºËüÃǶ¼ÓÐÏîÊý¡¢´ÎÊý¡¢ÏµÊýÂð£¿Èç¹ûûÓУ¬¾Í¿ÉÒÔ²»ÌîÁË. 2.5x?5 5a Õûʽ 6a2?1 ?2x3y2?x2?3 Ïî ?3x2y 2.5x¡¢5 6a2¡¢-1 ?2x3y2¡¢x2¡¢?3 5 1 2 1 3 ´ÎÊý ?3 5 ϵÊý ½Ìʦ×ܽ᣺±í¸ñÇ°ÃæÈý¸öÕûʽÓÐÏîÊýºÍ´ÎÊý£¬ºóÃæÁ½¸öÊǵ¥Ïîʽ£¬ÓдÎÊýºÍϵÊý Àý4ÈçͼËùʾ£¬ÓÃʽ×Ó±íʾԲ»·µÄÃæ»ý£®
µ±R=15 cm£¬r=10 cmʱ£¬ÇóÔ²»·µÄÃæ»ý£¨?È¡3.14£©£®
ѧÉú»î¶¯£ºÏȶÀÁ¢Íê³É£¬ÔÙС×é½»Á÷ÌÖÂÛ. ʦÉúºÏ×÷̽¾¿£ºÓÃʽ×Ó±íʾԲ»·Ãæ»ý.
½Ìʦ×ܽ᣺Բ»·Ãæ»ýµÈÓÚ´óÔ²Ãæ»ý¼õȥСԲÃæ»ý. ½â£ºÍâÔ²µÄÃæ»ý¼õÈ¥ÄÚÔ²µÄÃæ»ý¾ÍÊÇÔ²»· µÄÃæ»ý£¬ËùÒÔÔ²»·µÄÃæ»ýÊÇ?R2??r2£®
µ±R=15cm £¬r=10 cmʱ£¬Ô²»·µÄÃæ»ý£¨µ¥Î»£ºcm2£©ÊÇ ?R2??r2?3.14?152?3.14?102
=392.5.
Õâ¸öÔ²»·µÄÃæ»ýÊÇ392.5 cm2. Èý¡¢¹®¹ÌÍØÕ¹
Á·Ï°2£¨½Ì¿ÆÊéµÚ59Ò³µÚ1Ì⣩ 1.Ìî¿Õ£º
£¨1£©a¡¢b ·Ö±ð±íʾ³¤·½Ðεij¤ºÍ¿í£¬Ôò³¤·½ÐεÄÖܳ¤l£½ £¬ Ãæ»ýS£½ £¬µ±a£½2 cm£¬b£½3cmʱ£¬l£½ cm £¬ S£½ cm 2 £»
£¨2£©a £¬b ·Ö±ð±íʾÌÝÐεÄÉϵ׺Íϵף¬h ±íʾÌÝÐεĸߣ¬ÔòÌÝÐÎÃæ»ýS £½ £¬µ±a£½2 cm£¬b£½4 cm£¬h£½5 cmʱ£¬S£½ cm 2 £® ѧÉú»î¶¯£ºÐ¡×éºÏ×÷̽¾¿
½Ìʦ×ܽ᣺£¨1£©l?2?a?b? ¡¢S?ab¡¢l?10¡¢S?6£» £¨2£©S?2.
1?a?b?h¡¢S?15 2