10£®°ÑÒ»¸ö³¤Îª2m¡¢¿íΪ2nµÄ³¤·½ÐΣ¬ÑØÍ¼ÖÐÐéÏßÓüôµ¶¾ù·Ö³ÉËÄ¿éС³¤·½ÐΣ¬È»ºóÆ´³ÉÒ»¸öÕý·½ÐΣ¨Èçͼ1£©
£¨1£©ÇëÓÃÁ½ÖÖ²»Í¬µÄ·½·¨Çóͼ2ÖÐÒõÓ°²¿·ÖµÄÃæ»ý£¨Ö±½ÓÓú¬m£¬nµÄ´úÊýʽ±íʾ£©
·½·¨1£º£¨m+n£©2-4mn£»·½·¨2£º£¨m-n£©2£®
£¨2£©¸ù¾Ý£¨1£©ÖнáÂÛ£¬ÇëÄãд³öÏÂÁÐÈý¸ö´úÊýʽ£¨m+n£©2£¬£¨m-n£©2£¬mn¼äµÄµÈÁ¿
¹ØÏµ£»£¨m-n£©2=£¨m+n£©2-4mn£®
£¨3£©¸ù¾Ý£¨2£©ÌâÖеĵÈÁ¿¹ØÏµ£¬½â¾öÈçÏÂÎÊÌ⣺ÒÑ֪ʵÊýa£¬bÂú×㣺a+b=3£¬ab=1£¬Çóa-bµÄÖµ£®

·ÖÎö £¨1£©±¾Ìâ¿ÉÒÔÖ±½ÓÇóÒõÓ°²¿·ÖÕý·½Ðεı߳¤£¬¼ÆËãÃæ»ý£»Ò²¿ÉÒÔÓÃÕý·½ÐεÄÃæ»ý¼õÈ¥ËĸöС³¤·½ÐεÄÃæ»ý£¬µÃÒõÓ°²¿·ÖµÄÃæ»ý£»
£¨2£©ÓÉ£¨2£©¼´¿ÉµÃ³öÈý¸ö´úÊýʽ֮¼äµÄµÈÁ¿¹ØÏµ£»
£¨3£©½«a+b=3£¬ab=1£¬´úÈëÈý¸ö´úÊýʽ֮¼äµÄµÈÁ¿¹ØÏµ£¬Çó³ö£¨a-b£©2µÄÖµ£¬¼´¿ÉÇó³öa-bµÄÖµ£®

½â´ð ½â£º£¨1£©·½·¨Ò»£ºÒõÓ°²¿·ÖµÄÃæ»ý=£¨m+n£©2-4mn£»
·½·¨¶þ£ºÒõÓ°²¿·ÖµÄ±ß³¤=m-n£»¹ÊÒõÓ°²¿·ÖµÄÃæ»ý=£¨m-n£©2£®
£¨2£©Èý¸ö´úÊýʽ֮¼äµÄµÈÁ¿¹ØÏµÊÇ£º£¨m-n£©2=£¨m+n£©2-4mn£»
£¨3£©£¨a-b£©2=£¨a+b£©2-4ab=32-4¡Á1=5£¬
¡àa-b=¡À$\sqrt{5}$£®
¹Ê´ð°¸Îª£º£¨1£©£¨m+n£©2-4mn¡¢£¨m-n£©2£» £¨2£©£¨m-n£©2=£¨m+n£©2-4mn£®

µãÆÀ ±¾ÌâÖ÷Òª¿¼²éÍêȫƽ·Ö¹«Ê½£¬ÈçºÎ׼ȷµØÈ·¶¨Èý¸ö´úÊýʽ֮¼äµÄµÈÁ¿¹ØÏµÊǽâÌâµÄ¹Ø¼ü£®

Á·Ï°²áϵÁдð°¸
Ïà¹ØÏ°Ìâ

¿ÆÄ¿£º³õÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÌî¿ÕÌâ

20£®¼ÆË㣺$\frac{2a}{a+b}$•$\frac{{a}^{2}-{b}^{2}}{2ab}$•$\frac{1}{a-b}$=$\frac{1}{b}$£®

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º³õÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÑ¡ÔñÌâ

1£®¡ÏAOCÓë¡ÏBOCÊÇÁÚ²¹½Ç£¬OD¡¢OE·Ö±ðÊÇ¡ÏAOCÓë¡ÏBOCµÄƽ·ÖÏߣ¬ÊÔÅжÏODÓëOEµÄ¼Ð½ÇΪ£¨¡¡¡¡£©¶È£®
A£®60¡ãB£®65¡ãC£®90¡ãD£®80¡ã

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º³õÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÑ¡ÔñÌâ

18£®Èç¹ûÓÃ×ܳ¤Îª60mµÄÀé°ÊΧ³ÉÒ»¸ö³¤·½Ðγ¡µØ£¬É賤·½ÐεÄÃæ»ýΪS£¨m2£©£¬Öܳ¤Îªp£¨m£©£¬Ò»±ß³¤Îªa£¨m£©£¬ÄÇôS£¬p£¬aÖÐÊDZäÁ¿µÄÊÇ£¨¡¡¡¡£©
A£®SºÍpB£®SºÍaC£®pºÍaD£®S£¬p£¬a

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º³õÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÑ¡ÔñÌâ

5£®ÏÂÁз½³ÌÖУ¬ÊǶþÔªÒ»´Î·½³ÌµÄÊÇ£¨¡¡¡¡£©
A£®x=1-2yB£®$\frac{1}{x}$=1-2yC£®x2=1-2yD£®x=z-2y

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º³õÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÑ¡ÔñÌâ

15£®ÏÂÁмÆËãÕýÈ·µÄÊÇ£¨¡¡¡¡£©
A£®am•a2=a2mB£®£¨a3£©2=a3
C£®x3•x2•x=x5D£®a3n-5¡Âa5-n=a4n-10

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º³õÖÐÊýѧ À´Ô´£º ÌâÐÍ£º½â´ðÌâ

2£®Ä³»·±£Æ÷²Ä¹«Ë¾ÏúÊÛÒ»ÖÖÐÂÐͲúÆ·£¬ÒÑ֪ÿ¼þ²úÆ·µÄ½ø¼ÛΪ40Ôª£¬¾­Ïú¹ý³ÌÖвâ³öÏúÊÛÁ¿y£¨Íò¼þ£©ÓëÏúÊÛµ¥¼Ûx£¨Ôª/¼þ£©´æÔÚÈçͼËùʾµÄÒ»´Îº¯Êý¹ØÏµ£¬Ã¿ÄêÏúÊ۸òúÆ·µÄ×Ü¿ªÖ§z£¨ÍòÔª£©£¨²»º¬½ø¼Û³É±¾£©ÓëÄêÏúÊÛy£¨Íò¼þ£©´æÔÚº¯Êý¹ØÏµz=10y+42.5£®
£¨1£©ÇóyÓëxÖ®¼äµÄº¯Êý¹ØÏµÊ½£»
£¨2£©ÊÔÇó³ö¸Ã¹«Ë¾ÏúÊ۸òúÆ·Äê»ñÀûw£¨ÍòÔª£©ÓëÏúÊÛµ¥¼Ûx£¨Ôª/¼þ£©µÄº¯Êý¹ØÏµÊ½£¨Äê»ñÀû=ÄêÏúÊÛ×ÜÊÕÈë½ð¶î-ÄêÏúÊÛ²úÆ·µÄ×ܽø¼Û-Äê×Ü¿ªÖ§½ð¶î£©£»µ±ÏúÊÛµ¥¼ÛxΪºÎֵʱ£¬Äê»ñÀû×î´ó£¿×î´óÖµÊǶàÉÙ£¿
£¨3£©Èô¹«Ë¾Ï£Íû¸Ã²úÆ·Ò»ÄêµÄÏúÊÛ»ñÀû²»µÍÓÚ57.5ÍòÔª£¬Çë¸ù¾Ýº¯ÊýͼÏóµÄÐÔÖÊÈ·¶¨xµÄȡֵ·¶Î§£®

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º³õÖÐÊýѧ À´Ô´£º ÌâÐÍ£º½â´ðÌâ

19£®Èçͼ£¬Õý·½ÐÎOEFGÈÆ×ű߳¤Îª30µÄÕý·½ÐÎABCDµÄ¶Ô½ÇÏߵĽ»µãOÐýת£¬±ßOE¡¢OG·Ö±ð½»±ßAD¡¢ABÓÚµãM¡¢N£®
£¨1£©ÇóÖ¤£ºOM=ON£»
£¨2£©ÉèÕý·½ÐÎOEFGµÄ¶Ô½ÇÏßOFÓë±ßABÏཻÓÚµãP£¬Á¬½áPM£®ÈôPM=13£¬ÊÔÇóAMµÄ³¤£»
£¨3£©Á¬½ÓMN£¬Çó¡÷AMNÖܳ¤µÄ×îСֵ£¬²¢Ö¸³ö´ËʱÏß¶ÎMNÓëÏß¶ÎBDµÄ¹ØÏµ£®

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º³õÖÐÊýѧ À´Ô´£º ÌâÐÍ£º½â´ðÌâ

20£®Èçͼ£¬BEÊÇ¡ÑOµÄÖ±¾¶£¬AÊÇBEÑÓ³¤ÏßÉÏÒ»µã£¬¹ýAµã×÷¡ÑOµÄÒ»ÌõÇÐÏߣ¬ÇеãΪD£¬¹ýBµã×÷BC¡ÍADÓÚC£¬½»¡ÑOÓÚµãF£¬Á¬½ÓBD£®
£¨1£©ÇóÖ¤£ºDF=DE£»
£¨2£©ÈôtanA=$\frac{1}{2}$£¬DC=3£¬Çó¡ÑOµÄ°ë¾¶£®

²é¿´´ð°¸ºÍ½âÎö>>

ͬ²½Á·Ï°²á´ð°¸