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试卷答案
一、选择题 1~5 DBDCC 6~10 BABBA 一、填空题
1 212、?4
11、13、y??1x?12 22 515、50?
14、
二、解答题
(2018??)??16.(1)
011?2?(?) 321解:原式?1??4
314 ?
3(m?3)?(m?2)(m?2) (2)
解:原式?m2?6m?9?(m2?4)
?m2?6m?9?m2?4 ??6m?13
217.解:原式?x2?y2?(x2?2xy?y2?2xy?2y2?(?2y)
?x?y?x?2xy?y?2xy?2y?(?2y) ?4xy?2y?(?2y) ??2x?y
???22222??2??2x?1?0,?y?3??0且2x?1??y?3??0
22?2x?1?0,?y?3??021?x?,y??32
把x?12,y??3代入上式,得
原式??2?12?(?3) ??4
三、解答题: 18(1)
(2)BB??6
(3)S?ABC?172 19证明:
?CE∥AB(已知)??B??BCE(两直线平行,内错角相等)
?D是BC的中点?BD?CD(中点的性质)
在?ABD和?ECD中???ABD??EDC(对顶角相等)?BD?CD???ABD??ECD??ABD??ECD(ASA)
?AD?ED(全等三角形对应边相等)?D是AE的中点20.(1)120 (2)54
(3)选择线路“E拜相武侯祠”的学生人数:
1200?12?120(人) 120答:选择“拜武侯祠”学生有120人221.(1)(a?b?c)?a2?b2?c2?2ab?2bc?2ac
(2)由(1)可得:
1?a?b?c?2?(a2?b2?c2) 21 ?122?60
2 ?42
11(2)S阴影?a2?b2??a?b?a?b2
22111 ?a2?b2?a2?ab?b2
2221 ?a2?b2?ab
212 ??a?b??ab
21 ?152?35
2 ?95 22、解:(1)连接AB过D作DT∥AE
ab?bc?ac?????????????C??1??4?180?
?C?90???1??4?90??AE∥BF??BAE??ABF?180???CAE??CBF?90??AD平分?CAE,BD平分?CBF??2??3,?5??6又??2??3??5??6?90???3??6?45?A123EC
78DTB456F?AE∥DT??3??7?AE∥DT,AE∥BF?DT∥BF??6??8??7??8??3??6?45?(2)?AC?BC??1??3?AD?BD
??DAB??ABD??2??4在?ACD和?BCD中??AC?BC??2??4??AD?BD??ACD??BCD(SAS)??5??6
??ADB?45???5?22.5??AD?BD,?5??6?AB?CD?AB?CG,BC?BC??ACG??BCG?12?ACB?45???5??2??ACG?45???2?22.5??AD平分?EAC??2??EAD?22.5? ??EAD??5?CD∥AE(3)
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