»ª¶«Ê¦´ó°æ°ËÄ꼶ÊýѧÉϲáÆÚÖÐÊÔÌâ¼°´ð°¸2Ì×

2S£½2£«2£«2£«2£«2£«¡­£«2£«2£¬ ½«ÏÂʽ¼õÈ¥ÉÏʽµÃ2S£­S£½2201£­1£¬ ¼´S£½2201£­1£¬

¼´1£«2£«22£«23£«24£«¡­£«2200£½2201£­1. ÇëÄã·ÂÕÕ´Ë·¨¼ÆË㣺

(1)1£«2£«22£«23£«24£«¡­£«210£»

(2)1£«3£«32£«33£«34£«¡­£«3n.(ÆäÖÐnΪÕýÕûÊý)

2345200201

²Î¿¼´ð°¸

Ò»¡¢Ñ¡ÔñÌâ

1.B 2.B 3.C 4.A 5.D 6.C 7.B 8.A 9.D 10.C ¶þ¡¢Ìî¿ÕÌâ

11.3 12.2£­3 13.49 14.(1£«x£­y)(1£­x£«y) 15.36 16.8 17.6 18.£­17 Èý¡¢½â´ðÌâ 19.£¨1£©1 £»£¨2£©5x£­3

20.½â£º(1)(m£«1)2(m£­1)2 (2)(x£«3y)(x£­3y£«1) 21.a2£«b2£½30£¬(a£­b)2£½24

22.½â£º(1)¡÷ADF¡Õ¡÷CBE£¬¡÷ABE¡Õ¡÷CDF£¬¡÷ABC¡Õ¡÷CDA (2)ÂÔ

23.½â£ºn2£«nµÄÕûÊý²¿·ÖÊÇn.ÀíÓÉ£º¡ßn2£«n£½n£¨n£«1£©£¬¶øn2£¼n£¨n£«1£©£¼£¨n£«1£©2£¬¼´n£¼n£¨n£«1£©£¼n£«1£¬ÓÉÓÚnΪÕýÕûÊý£¬¡àn2£«nµÄÕûÊý²¿·ÖÊÇn.

24.½â£ºÑÓ³¤ADÖÁµãM£¬Ê¹DM£½DA£¬Á¬½áCM£¬Ò×Ö¤¡÷ADB¡Õ¡÷MDC(SAS)£¬¡àCM£½AB£½5£¬ÔÚ¡÷ACMÖУ¬AC£­CM£¼AM£¼AC£«CM£¬¼´7£­5£¼2AD£¼7£«5£¬¡à1£¼AD£¼6.

£«

25.½â£º(1)211£­1 (2)ÉèS£½1£«3£«32£«33£«34£«¡­£«3n£¬½«µÈʽÁ½±ßͬ³ËÒÔ3µÃ3S£½3£«32£«33£«34£«35£«¡­£«3n

1

£¬ËùÒÔ3S£­S£½3

n£«1

£­1£¬¼´2S£½3

n£«1

n1

3n1£­1£­1234n3£­1£¬ËùÒÔS£½£¬¼´1£«3£«3£«3£«3£«¡­£«3£½ 22

£«

£«