2021-2022学年北京市人大附中分校九年级（下）限时练习数学试卷七（附答案详解）

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2021-2022
ᓅᜧ▬ᑖ᪥
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9wᫀyz᪆1.ூwᫀ௃Aூz᪆௃z~᪷1Ḅsᙊᱯᦑ⌱:A.᪷1Ḅsᐸᑣ⌲Sᑨᓽ.⚪⌕ὃ1z⚪ḄᐵḄ12.ூwᫀ௃Bூz᪆௃z~T-40,b<0,¡c—b>0,⌱⚗¤¥§a<0,c>0,¡ac<0,¡C⌱⚗£¤¥3,c<3,a+c<0,¡஺⌱⚗£¤¥ᦑ⌱~B.⚪ᵫ1Faஹªc«hY¬Ḅᜧᐵ;®¯ᑨ°⌱⚗Ḅh┯.⚪⌕ὃ²³ᦪḄ«hYᨵᐵḄFᐵᑨa,b,cḄ¤µy«hY.3.ூwᫀ௃Dூz᪆௃ூᑖ᪆௃·⚪ὃ²z¡ᐗS¹º»¼½¾¿ÀÁÂÃᑣz⚪Ḅᐵ.º»¼ᑭᵨÆÇÈᐗÃWqzᓽ.ூzw௃z~,7=3জ(3%—8y=14@জx3-ঝU~5y=-5,ᓽy=-l,Êy=-1ËᐭজU~%=2,ᑣº»¼Ḅzz~1ᦑ⌱~D.4.ூwᫀ௃Cூz᪆௃z~᪷⚪ÎU~7140x35=249900=2.5x10527nᦑ⌱~C.t10⚓ᐳ28⚓

10ᐜÑÂFASTḄÒÓ☢Ô☢ÕÖ᪷×ØÙᦪÃ⊤Ûqᩭ×ØÙᦪÃḄ⊤ÛÝaxlO%ᐸ>lW|a|<10,n᦮ᦪ.¥nḄY᧕┯ᵫ!2499002250000ᨵ6àᡠ]]¥ri=6—1=5.·⚪ὃ×ØÙᦪÃ⊤ÛâᜧḄᦪḄºÃ㥥anYᐵ.5.ூwᫀ௃Aூz᪆௃ூᑖ᪆௃⚪⌕ὃ²¤ä(Ḅᑁ᜜½¾Ñ¤æ(Ḅᑁ¤ç(Ḅᑁz⚪Ḅᐵ.᪷¤æ(Ḅᑁyy¤ç(ḄᑁyèÝWU¤æ(Ḅjᑁlé!108஺y¤ç(Ḅᑁlé!120஺ᯠë᪷ìḄᑁyᳮUîï.ூzw௃z~ᵫ⚪ÎU~¤ç(Ḅjᑁlé!120஺¤æ(Ḅjᑁlé!108஺•••^BOA=360°-120°-108°=132°,vAO=BO,180°-132°A/.ABO=^OAB=-------=24°ᦑ⌱A.6.ூwᫀ௃Aூz᪆௃z~ðÝ=(XSe).Sk2a2a7a-b(a—b)2a=-----------♦--------2aa—b_a-b-2%Q—b=2ñ-ðÝ=ò=ñ2ᦑ⌱:A.ᐜÊóôᑁõᑖÖÑÂóôᑁḄÇÃஹö-Êᑖ÷øÝᑖzᨬëÑÂùÃú¯ËᐭÑÂU.

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OEF,&OB=6,.••CḄᙶ᪗(6,4),ᦑ⌱:B.᪷-Ḅᭆ/&ᑮBC஻EF,2345OBC-AOEF,᪷-67Ḅឋ9ᑡ;!<=>ᓽ@.A⚪ὃDḄḄᭆ/ஹ67Ḅឋ9FGHᣚḄJKஹLM$NO⚪ḄᐵQ.8.ூᫀ௃Cூ᪆௃ூᑖ᪆௃A⚪ὃDS767ḄMᵨ-V7W7X⚪.YA⚪ḄᐵQZᔠᑭᵨ67]ᦪS767.✌ᐜᑖ᪆᪷-⚪a&JKS767AaONஹABOM,bcdJKS767e&N஺ஹM஺Ḅ%f23ᑭᵨMN=MO+NOᓽ@e;ᫀ.ூ௃ᵫ⚪a&ZJV=43஺NM=35஺AO=135m,BO=AO-AB=95m,ᙠRtzMONtanN=—=tan43°,NOAn•NO=-------x150m,tan430ᙠiBOMtanM=—=tan35°,BO•MO=x135.7m,tan35°j12⚓ᐳ28⚓

12MN=MO+NO=135.7+150«286m.ᦑ⌱C.9ூᫀ௃Cூ᪆௃ூᑖ᪆௃A⚪ὃDnoX⚪]ᦪp᪷-PqᙊḄstuv᪀⌼;ᐰz67Ḅ
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