2021-2022学年贵州省黔西南州八年级（下）期末数学试卷（附答案详解）

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2021-2022
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uvᨬxyzᓫ<|࠷Ḅ~].sssᨒ◖sssyz/࠷111311121615

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ḄÏᑖḄ´³µᵨy¸¹ºxSCḄᦪᐵ¼Ô"y=2%+511.᝞8ÕeABCQḄfghACஹ8஺ij=BO,ÎB஺×CHJ.AB=B”ÙÚOH,஺4=6,SÕeABCD=48ᑣOHḄ9

2A.1B.3C.3(m—1)D.|(m-2)13.ÛgeḄdᑖN96,8,10,ÜÝÞᨬßdIḄà914.áᨬâãä᪷Ô3åãT"æçãä᪷Ôᑣ⊈=.15.᝞8_éeABCDḄ⚔BA,B,CḄᙶ᪗ᑖN9(1,1),(4,1),(4,4),íhy=x+b¸_éeABCDḄdîïᨵjBᑣ6ḄO".16.᝞8ᙠðeABC஺*஺9fgh4cḄ*BÎB஺ḄíhᑖN¸dAB,CDj=BE,F.ÙÚBñjAC=BM,ÙÚOE,஺ò4COB=60°,OF=CF,ó±!ôõ|@BF1OC,OM=CMঝWDAE÷ABCFøঞcdeEBFD"ÕeøটAB|BC=g|1.ᐸ*_JḄ"(ýþÿ)17.
:(1)(1-V2)2+3V10V5(2)754+6V24.18.᝞ᦪḄ(2,0),6(0,1),ᦪy=-xḄC.(1)ᦪḄ᪆;(2)4஺஺Ḅ☢#.19.ᙠᩩ'()ᔣḄ+Ḅ,ᨵ᩟/C,+01ᨵ2345A,8,ᐸ7ZB=4C,ᵫ9:1ᵫCᑮAḄ<=ᙠ>?@9᩟ABC᩟D45EFᙠ+0GH

3345HG4ஹHஹBᙠᩩJKL),NGOᩩᑖ᪆ஹ᦮ᳮQ᝞?᦮Ḅᦪᑖ᪆⊤ᙳᦪ7ᦪᦪB{}~87.488a43.44|}~87.4b9527.64(1)a—,b=(2)ᡂ85ᑖ(85)^LA\
z᪥{ஹ|}~ᡂAḄefᦪ(3)᪷^Lᑨ¡¢3}~Ḅᡂ£N_`ᳮᵫ.(¤◤⌕X3§¨_`ᑨ¡Ḅᔠᳮឋ)21.᝞ᙠ«0¬ABC஺7AD//BC,AB=AD=CD=^BC,ᑖ^B,Dᙊ®ஹᜧḄbA°±²³2³M,²´KAMBCE,µ¶BD,DE.(1)·«0¬A8E஺V¸¬(2)CE=1,Ḅb.22.¹ᔠº»e¼n½¬¾ᐶÀÁwḄÂeÃᙠÄᐳÂẆǽ¬ḄᢚÉ.᝞,ACA½¬ABCDḄʧK,Ë0ABÌAEᢚÉÍ3ÎᙠACLḄMᜐË0C஺ÌCFᢚÉÍ஺ÎᙠACLḄNᜐ.Ð4⚓ᐳ18⚓

4(1)·«0¬AECFVm«0¬(2)48=6,AC=10,«0¬AECFḄ☢#.23.AÞßàáâ⁚9áâäåæçènᵬஹê2:ëìᓱ.îëìᦪAxð,ᡠ◤ìᵨA)ᐗôyxḄᦪᐵ÷᝞ᡠø.᪷7ùᑡT⚪:(1)ᑖè⌱ýᵬஹê2:ëìᓱëìðyᐵxḄᦪ᪆.(2)8Ḅᙶ᪗
BḄ▭.(3)᱆᱆ᜓ240ᐗᵨᙠḄ⌱"#$ᓱᑜ'(ᐔ20x24.*▅,-./0☢23ᙶ᪗67ᨵ9Pi(Xi%)>2஺2ஹ2)᪷BCDEᳮ.G/9HḄIJ2〈2=—N23+(71—%)2,ᱯTᙢ᝞W/\01ᨴ)[2(\2])ᡠᙠḄ2_`ᙶ᪗abᔠᡈ0eᙶ᪗aᡈᚖ2ᙶ᪗aghij9HḄIJklGmᓄoP1P2=%pᑗᡈ1%pr21s᝞:./P(3,l)v2(1,-2),ᑣj9HḄIJPQ=(3—1>+(1+2)2=V13.᪷B{|ᩞᧇᑡ⚪(1)./4(2,3),5(-1,-2),ᑣA,89HḄIJo.(2)./M,Nᙠpᩩ0e)aḄ2_|ᵨḄᙶ᪗o-2,NḄᙶ᪗o3,ᑣM,N9HḄIJo.(3)᝞ᙠ0☢23ᙶ᪗67./4(0,4),8(4,2),ᙠxa|ᔲᙠp>P4+PBḄᨬ(ᙠg>Ḅᙶ᪗]PA+PBḄᨬ¡¢ᙠᳮᵫ.

525.᝞./ᙠ¤¥¦ABC஺7AB=2A/2,Eo§3_AC|p¨©DE.ªE«EF10E.¬_BC>DE,EFo®¯«°¦DEFG.¨©CG.(1)±°¦஺EFG¤¥¦.(2)CE+CGḄᔲoE(j²E;¢,ᳮᵫ.(3)´_µ஺E`¤¥¦ABCQ¶¯ᡠᡂḄ¸330஺gNEFCḄ¹ᦪ.»6⚓ᐳ18⚓

6¾ᫀÀ᪆1.ூ¾ᫀ௃Aூ᪆௃᪷B⚪a>0,⌱⚗7ÅᨵA⌱⚗p1¢ÆÇa>0.ᦑ⌱A.᪷BÉÊ᪷lᨵḄᩩËaN0,Ì⌲²ᑨÏᓽG.Ñ⚪ὃÓÔÉÊ᪷lᨵḄᩩËpᐗpÊ¢ÕlÀᨵᳮᦪḄᜧ׸ØÙÚᔊ7a20⚪ḄᐵÝ.2.ூ¾ᫀ௃Aூ᪆௃Aஹ62+82=102,Ø᪀ᡂ23ß3¦¤᦮ᦪCDᦪáᔠ⚪¡Bஹ22+2?â22,¢Ø᪀ᡂ23ß3¦ᦑ¢CDᦪ¢áᔠ⚪¡Cஹ1,1,ã¢ä¤᦮ᦪ¢CDᦪ¢áᔠ⚪¡Dஹ0.4,0.3,0.5䢤᦮ᦪ¢CDᦪ¢áᔠ⚪.ᦑ⌱A.᪷BCDᦪḄEÆÇ஺2+å=஺2Ḅß²¤᦮ᦪæoCDᦪᑨEᑣG.Ñ⚪ὃÓÔCDᦪḄEçpèCDᦪéêgÆÇ9²ᩩËজß²ᦪä¤᦮ᦪ¡ঝ9²¸ᦪḄ0¥ÀÕᨬᜧᦪḄ0¥.3.ூ¾ᫀ௃Cூ᪆௃.C,஺ᑖT஺1,08Ḅ7•••AB=2CD-20m,ᦑ⌱C.᪷Bß3¦7î_Eᳮ¾ᓽG.Ñ⚪ὃÓḄß3¦7î_Eᳮïðß3¦Ḅ7î_0e»ß¯ñջ߯Ḅpò⚪ḄᐵÝ.4.ூ¾ᫀ௃Aூ᪆௃ᵫCDEᳮAB2+BC2=AC2,^AB2+BC2=(V2)2=2,ᦑ⌱A.ᵫCDEᳮG2©óW.Ñ⚪ὃÓÔCDEᳮÙôïðCDEᳮ⚪ḄᐵÝ.

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2=|±2|=2,ᦑB┯ù¢áú⚪¡V2xV10=2V5,ᦑC¤üáᔠ⚪¡==3,ᦑ஺┯ù¢áú⚪¡V2ᦑ⌱C.᪷BÉÊ᪷lý'Ḅþᐵÿᑣ⌲⚗ᑨ.⚪ὃ᪷Ḅ⚪Ḅᐵ᪷Ḅᐵᑣ.6.ூᫀ௃Bூ᪆௃!ᑨ"#$%ABCO&'#$%Ḅ04=OC,OB=0D,ᳮᵫ᝞+0A=0C,OB=0D,#$%ABC஺&'#$%-./01&ᑖḄ#$%&'#$%3ᦑ⌱B.ᵫᑖḄ#$%&'#$%ᓽ789:;.⚪ὃ<&'#$%Ḅᑨ"=>./01&ᑖḄ#$%?&'#$%⚪Ḅᐵ.7.ூᫀ௃Cூ᪆௃@ABᦪDEF᣸ᑡ?11,11,12,13,15,16,ᡠJABᦪDḄKLᦪ?M=12.5࠷,Pᦪ?11࠷,ᦑ⌱C.@ABᦪDQRᑮᜧEF᣸ᑡU᪷DKLᦪVPᦪḄᭆXYᓽ7.⚪Z⌕ὃKLᦪஹPᦪ@]BᦪDᢥ᯿QRᑮᜧ-ᡈQᜧᑮR3Ḅab᣸ᑡ᝞cᦪDḄdᦪ᜻ᦪᑣᜐgKhLiḄᦪjABᦪDḄKLᦪ.᝞cABᦪDḄdᦪᏔᦪᑣKhldᦪDḄ&ᙳᦪjABᦪDḄKLᦪ.Y]BᦪDḄPᦪḄno9⚣ᦪᨬrḄsdᦪDtudᦪD⚣ᦪvᨬrwxyzPᦪjArdᦪD.8.ூᫀ௃Bூ᪆௃•,,}N3,b
vᙠᦪy=/exḄ.w]1V3,Q>/?,yxḄᜧRAfc<0,ᦑ⌱B.ᑭᵨᦪḄឋᓽ789AḄ.y⚪Z⌕ὃ<]ᦪ}Ḅᙶ᪗ᱯ=ᦪḄឋ⚪ᐵ.8⚓ᐳ18⚓

89.ூᫀ௃Aூ᪆௃ᵫ⚪C?0ABḄK}wCD14B,AB=16cm,CD=6cm,ᡠJAC==8cm,AD=BD,᪷D¥¦"ᳮ4D='AC?+CD2=10(cm),AD+BD-AB=2AD-AB=20-16=4(cm)ªᦑ«¬®¯°<4cm.ᦑ⌱A.᪷D±Ὺ³/%Ḅឋ´V¥¦"ᳮ7Y9A஺ஹ8஺Ḅ°ᑣ/W+BD-ABᓽ?«¬¯°Ḅ¹º.y⚪Z⌕ὃ<±Ὺ³/%Ḅឋ´J»¥¦"ᳮḄ¼ᵨ⚪Ḅᐵᳮ⚪½ᮣ¿ᵨᡠÀÁÂÃ⚪.10.ூᫀ௃Dூ᪆௃ᵫ78ÄÅÆᜩ9ÈÉḄÊËÌ5ᐗᦑAÏÐÑᔠ⚪½ªÄÅÆᜩᙠ2.50nᑁÖᦈÊËÌᦑ8ÏÐÑᔠ⚪½ªØÙ2.5km(x>2.5)ḄÝᑖÞᓟàáᦈ(8-5)+(4-2.5)=2(ᐗ)ᦑCÏÐÑᔠ⚪½ªØÙ2.5/on(x>2.5)ḄÝᑖḄãÉäᵨyæçèxéhḄᦪᐵêy=2(x-2.5)+5=2x,ᦑ஺┯ìÑᔠ⚪½ªᦑ⌱D.íî⌲⚗ᑨᓽ7.⚪ὃ]ᦪḄ¼ᵨ⚪Ḅᐵïð⚪½!ÏÁ.11.ூᫀ௃Aூ᪆௃ூᑖ᪆௃⚪ὃ<ñ%Ḅឋ´ò/³/%Ḅឋ´ñ%Ḅ☢ôõᐵ᪷Dò/³/%ö$ḄK0ឋ´Y8஺”=\BD.ᵫñ%Ḅឋ´89஺4=0C=6,OB=OD,AC1BD,ᑣ4c=12,ᵫò/³/%ö$ḄK0ឋ´89OH=BD,Uᵫñ%Ḅ☢ôY9BD=8,ᓽ789ᫀ.ூ௃•••#$%ABC஺ñ%•••0A—0C=6,OB=0D,AC±BD,AAC=12,vDHX.AB,:.BHD=90°,..஺”=ü

9•.•ñ%ABCDḄ☢ô=3x4CxBD=gx12xBO=48,:.BD=8,•••OH=-BD=4ª2ᦑ⌱412.ூᫀ௃Bூ᪆௃ூᑖ᪆௃⚪ὃ<]ᦪ}Ḅᙶ᪗ᱯஹ³/%Ḅ☢ôJ»ᦪ᪷D]ᦪ}Ḅᙶ᪗ᱯ89³d³/%ᙳÿ1,2Ḅ⚪Ḅᐵ.AOLy஺BFlyBGCGG,ᯠ#$%AஹBஹCஹD.EஹFஹGᔜḄᙶ᪗*+%,-./012ᑭᵨ☢678ᓽ:.ூ<௃>᝞@4஺lyB85_1.FBGLCGG.ᵫ⚪H:I>Aᙶ᪗(-1,2+m),Bᙶ᪗(1,-2+m),Cᙶ᪗(2,m-4),஺ᙶ᪗(0,2+m),Eᙶ᪗(0,m),ᙶ᪗(0,-2+TH),Gᙶ᪗(l,m-4).ᡠR'DE=2+m—m=2,EF=m—(-2+m)=2,BG=-2+m—(m-4)=2,ᡠR஺E=EF=BG=2,UV4஺=BF=GC=1,ᡠR@W▢YZᑖḄ☢6\]2x2X1x3=3.ᦑ⌱B.13.ூ<ᫀ௃8ூ᪆௃>•.Ḅf0ᑖg6,8,10,62+82=102ijᨬlf6mḄᓽnof8.᪷q⚪WᦪqsᵨtuvᳮḄ⌮vᳮyzᯠ#{|<.}⚪~⌕ὃtuvᳮ⌮vᳮḄ-ᵨ.14.ூ<ᫀ௃310⚓ᐳ18⚓

10ூ᪆௃>᪷q⚪HI2m—1=5,I?n=3.ᦑ<ᫀ>3.᪷qj᪷8ḄvIᑮ2nl-1=5,ᯠ#ᓽ:.⚪ὃj᪷8>j᪷8Ḅv⚪Ḅᐵ.ὃᨬj᪷8.15.ூ<ᫀ௃o3Wb43ூ᪆௃>•.•fA8CDAḄᙶ᪗(1,1),BḄᙶ᪗(4,1),CḄᙶ᪗(4,4),•••஺Ḅᙶ᪗(1,4)..ஹ=x+b8l=4+b,I>b=-3.y=x+b஺4=1+6,I>b=3.•••.y=x+bABCDḄf,bḄ¢o3-3SbS3.ᑭᵨḄឋ¤:$%஺Ḅᙶ᪗,ᑭᵨo¥ᦪ@¦mḄᙶ᪗ᱯ¨ᑖg$%.y=x+bB\஺ᓃḄ{ª:I%.y=x+bABCDḄf,6Ḅ¢.⚪ὃo¥ᦪ@¦mḄᙶ᪗ᱯ¨R«Ḅឋ¤ᑭᵨ᩽▲®¯%ᓃḄᨬᜧ«ᨬ±⚪Ḅᐵ.16.ூ<ᫀ௃জঝঞটூ᪆௃>•.•fABCO஺ACḄW•••AABC=JCDAE=^BCF=90°,OA=OC,OB=-AC=OC,AD=BC,2•(BOC=60°,•.¶OBC]f,.OB=OC,•3ᙠOCḄᚖ¹ᑖ.m•OF=CF,jᙠOCḄᚖ¹ᑖ.mABF1OC,0M=CM,ᦑজºvOA=OC,/-DCA=Z.CAE,COF=(AOE,¶COFWZMOEQ4sA),ACF=AE,OE=OF,

11-AD=BC,DAE=Z-BCF,/.*DAE^^BCF+SAS^ᦑঝº--CF=AE,:.DF=BE,•DF“BE,f஺»¹|f••OBC=60°,•EBO=30°,♦EBO=FBO,•BO1EF,••fE8U¾¿ᦑঞºvZ.ACB=60",•••ABAC=30°,-.AB-BC=V3>1,ᦑটºᦑ<ᫀ>জঝঞট.᪷qḄឋ¤I^OBC]fĪyzBFᚖ¹ᑖOC,:ᑨÆজºᑭᵨAS4¶C஺ȶAOE,ICF=AE,OE=OF,2ᑭᵨS4Sᓽ:yz4DAE^/^BCF,ᦑঝºᑭᵨoÉf¹|Ê,]:yzfOEBF¹|f2yzBO1EF,:Ëf¿:ËঞºᑭᵨÌ30஺ḄḄឋ¤:Ëটº.⚪fÍᔠ⚪~⌕ὃḄឋ¤¿Ḅឋ¤]fḄᑨvឋ¤Ì30°ḄḄឋ¤ᐰ]Ḅᑨvឋ¤]ËÐyzf஺EBF¿⚪Ḅᐵ.17.ூ<ᫀ௃>Ò1¾Ò1-Ó¾2+3Ô+⍩=1-2V2+2+3V2=3+V2=3V6+V6-2V6-2Ö.ூ᪆௃Ò1¾ᐜ{|Øᐰ¹Ḅs+j᪷8Ḅ◀®s+2{|ÚÛs+ᓽ:;Ò2¾ᐜᓄ2{|ÚÛs+ᓽ:.⚪~⌕ὃj᪷8ḄÞᔠs+<Ḅᐵ,-Ḅs+®ᑣḄ.12⚓ᐳ18⚓

1218.ூ<ᫀ௃>(1)o¥ᦪy=kx+b,•••o¥ᦪḄ@¦4(—2,0),8(0,1),.•.{”+b=0,Iàá3=1U=1ᦑo¥ᦪ⊤ã8>y=|x+1,(2)ᵫà=ä+1,Ià=å[y=-x[y=-•••c(-1|).•¶40CḄ☢6:|x2x|=|,ூ᪆௃(1)ᑭᵨèvéᦪ®$ᓽ:(2)᪆8ὶëᡂÉ,É$ICḄᙶ᪗ᯠ#᪷q☢678$Iᓽ:.⚪ὃèvéᦪ®$o¥ᦪḄ᪆8íᩩ.,⚪Ḅ☢6èvéᦪ®⚪Ḅᐵ.19.ூ<ᫀ௃>(1)ᳮᵫ>ᙠACHBW,:CH2+BH2=(1.2)2+(0.9)2=2.25,BC2=2.25,•••CH2+BH2=BC2,•.¶CHBÄ᩟ñCᑮòfḄᨬóô(2)AC=xᓟöᙠRtZkACHWᵫ÷ËIAC=x,AH=x-0.9,CH=1.2,ᵫtuvᳮI>AC2=AH2+CH2•••/=(ùo0.9)2+(1.2)2,úûIx=1.25,<>üᩭḄô.ACḄ01.25ᓟö.ூ᪆௃(1)᪷qtuvᳮḄ⌮vᳮ<ᓽ:(2)᪷qtuvᳮ<ᓽ:.}⚪ὃtuvᳮḄ-ᵨᐵ᪷qtuvᳮḄ⌮vᳮ\vᳮ<.20.ூ<ᫀ௃8187ூ᪆௃>(1)ᵫþÿḄᡂᦪa=81(ᑖ)Ḅᡂ᣸80,81,82,85,86,88,90,92,95,95,ᑣḄᦪb==87(ᑖ)

13ᦑᫀ81,87(2)240x+300x5=375()!"#᪥%ஹᡂ'(Ḅ)*ᨵ375(3)Ḅᡂ,(ᳮᵫ᝞0Ḅ12,3ᡂ45.(1)ᵫᦪḄ5789஻Ḅ;ᵫᦪḄ5789ᓽ(2)ᵫ#᪥%ஹᐳᨵᦪ>?ᡂ'(Ḅ)*ᡠᓰḄBCᓽ(3)ᵫ12DEᑨGᓽ.H⚪ὃKLᵨ᪵O!"PQ?RᦪஹᦪḄ5712ḄS7ᦪTᦪU9VWᦪᨬYḄᦪ.ᦪTZ[\ᦪU]3ᑮᜧ(ᡈ]ᜧᑮ3)bc᣸ᑡeᨬfḄghᦪ(ᨬfihᦪḄjᙳᦪ)lmn\ᦪUḄᦪ᝞oᦪḄᭆqrst(tᦪUᢥ⌕8bc᣸ᑡwx9┯.21.ூᫀ௃(1)|}᝞~AEBODM,••AB=AD,BM=DM,•••4MᚖjᑖBD,•.BE=DE,4BAE=Z-DAE,-AD//BC,•Z.DAE=/-BEA,•BAE=BEA,•AB=BE'•AB=AD=BE=DE,ABE஺T.(2)•••BE=4D=CD=BC,•.CE=BE=AD=CD=1,BC=CE+BE=2,vAD//CE,AD=CE,AEC஺TjE•.CD//AE,vAE1BD,:.BDC=Z.BFE=90°,•••BD=yjBC2-CD2=V22-l2=V3.ூ᪆௃(1)AE8DF,8MஹDM,ᐜᵫ4B=AD,=|}AMᚖjᑖBD,2BE=DE,3AD஻BC,ᑣN8AE=/.DAE=BEA,ᡠ?4B=BE=AD^DE,ᑣABE஺T(2)ᵫBE=AD=CDCE=BE=4஺=CD=1,|}AECQTj14⚓ᐳ18⚓

14ECD஻4E,ᑣNBDC=48FE=90஺ᓽ᪷U5ᳮ898஺Ḅ.H⚪bὃKḄᑨ5ឋஹjEḄᑨ5ឋஹᚖjᑖḄᑨ5ஹῪḄ“ᔠ[”ஹ5ᳮ¤¥|}AET8஺ḄᚖjᑖT⚪Ḅᐵ§.22.ூᫀ௃প|}•.•ABCDª.-.AD//BC,AB//CD.■■Z.BAC=Z.DCA,ᵫᢚ¬Ḅឋ¤I,Z.EAC=^Z.BAC,Z.FCA=^Z.DCA,•Z-EAC=Z.FCAf^AE//CF,5ADIIBC,AECFjE(2)ᙠRtAABCAB=6,AC=10,ᵫ5ᳮBC=V102-62=8,ᵫᢚ¬Ḅឋ¤/-ABC=Z.AME=90°,BE=EM,ᙠRtACEMCM=AC-AM=10-6=4,CE=x,®i¯BE=EM=8-x,ᵫ5ᳮME2+CM2=EC2,ᓽ(8—%)2+16=x2,x=5,•••ᵫ(1)AECFjES678AECF=EC•CD=5X6=30.ூ᪆௃(1)°UªḄឋ?Rᢚ¬Ḅឋᓽᑮ4F஻CE,AE//CF,ᓽᑮAECFTjE(2)CE=x,ᑣEM=BE=8-x,CM=10-6=4,ᑭᵨ5ᳮᓽᑮCEḄD²9AECFḄ☢´.O⚪µ⌕ὃKLᢚ¬¶⚪?RªḄឋḄ·ᵨᢚ¬T[¸¹º»ᣚ½¾¿¹º,ᢚ¬Áe~ḄÂÃᜧ3t»Ä»ᓄ¹ÆùÆÇ.23.ூᫀ௃(1)⌱Éᵬ¸ËÌᓱËÌÎyᐵxḄÏᦪ᪆ÐÑ=Ò•••(5,100)ᙠ#Ïᦪ~ÓÒ100=5k,k=20,ᓽ⌱Éᵬ¸ËÌᓱËÌÎyᐵxḄÏᦪ᪆Ðy=20x⌱ÉÔ¸ËÌᓱËÌÎyᐵxḄÏᦪ᪆Ðy=ax+b,

15•(0,100),(20,300)ᙠ#Ïᦪ~ÓÒ,.(b=100“(20a+b=300'ᓽ⌱ÉÔ¸ËÌᓱËÌÎyᐵxḄÏᦪ᪆Ðy=10%+100(2)Õ20%=10%+100,Ö=10,×Ø=10Î20x=200,•BḄᙶ᪗(10,200),BḄÛ▭S7T×ÝÞßàËÌ10WÎi¸ËÌᓱËÌ[᪵áT200ᐗ(3)×y=240Î⌱ÉᵬÎ240=20%,ã=12,⌱ÉÔÎ10x+100=240,x=14,•••14>12,••ää᱆᱆æᜓ240ᐗèᵨääᙠ#ÞßàḄËÌ⌱ÉÔ¸ËÌᓱᑜê.ூ᪆௃(1)᪷UÏᦪ~ÓḄᦪU?"ê9⌱ÉᵬஹÔi¸ËÌᓱËÌÎyᐵxḄÏᦪ᪆Ð(2)᪷U(1)ḄëoÕᵬÃÔ¹ÆḄÏᦪ;Ç89ÇÆḄx,89y,ᓽᑮ8Ḅᙶ᪗ᑏ9B⊤îḄÛ▭S7ᓽ(3)Zy=240ïᐭᵬÃÔ89ÇÆḄxḄ;ᯠeB,ᜧ3ᓽ.O⚪ὃK[WÏᦪḄÆᵨO⚪Ḅᐵ§T}ò⚪SᑭᵨᦪëᔠḄóô.24.ூᫀ௃V345ூ᪆௃(1)4B=J(2++(3+2õ=V34,ᦑᫀV34(2)MN=3-(-2)=5,ᦑᫀ5(3)᝞~öBᐵx¿Ḅ¹ºB',48'x¿P,PB,HÎP4+PBḄ;ᨬ3.Ai'ஹ:B-9B'A(0,4),B'(4,-2),AB'Ḅ᪆Ðy=-|x+4,16⚓ᐳ18⚓

16Õy=0
x=p•.P(|0)•••PA+PB=PA+PB'=AB'=V42+62=2vH,PA+PBḄᨬ3;2g.(1)ᑭᵨiføùúÐ8ᓽ(2)ᑭᵨiføùúÐ8ᓽ(3)᝞~öBᐵx¿Ḅ¹ºB',4B'x¿P,P8,HÎP4+PBḄ;ᨬ3.O⚪ὃK¿¹ºᨬû¶⚪5ᳮ¤¥⚪Ḅᐵ§T)xᑭᵨ¿¹ºüᨬû¶⚪¾ὃýὃ⚪þ.25.ூᫀ௃(1)|}öEK_1.BCK,e/,1஺஺ᑣNEKF=NELO=90஺,Fᙠ8c᝞1,FᙠBCḄ᝞2,•••48CZ)AB=CB,AD=CD,Z.B=Z.ADC=90°,4BCA=/.BAC=45",^DCA=Z.DAC=45°,:.Z.BCA=Z.DCA,•EK=EL,vEKC=ELC=KCL=90°,.EKCLDE/G1KEL=FED=90,••Z.FEK=(DEL=90°-(FEL,FEgADELIASA),•DE=FE,OE/G.(2)CE+CGḄᳮᵫ4EOG=4ADC=90°,••Z.CDG=2LADE=90°-4CDE,•CD=AD,GD=ED,•••"CDG0ZMDE(S4S),•CG=AE,:.CE+CG=CE+AE=AC,CE+CGḄvB=90°,AB=CB=2V2,

17.-.AC=J(2#2+(2ᱥ2=4,:.CE+CG=4,&'4.(3)NAOE=30°᝞1,()ᙠBC•••4DEF=90°,DEC=/.ADE+^DAC=30°+45°=75°,•••4CEF=DEF-Z.CED=90°-75°=15°,•••EFC=180°-Z.CEF-BCA=180°-15°-45°=120°*NCCE=30஺᝞2,(Fᙠ8cḄ•••DEF=90°,4AED=Z.CDE+Z.DCA=300+45°=75°,4CEF=180°-4DEF-/.AED=180°-90°-75°=15°,•••EFC=BCA-CEF=45°-15°=30°,+ᡠ-LEFC=120஺ᡈ4EFC=30".ூ᪆௃প3EK1BCK,EZ,1CDᐜᵫABCO56NBCZ=ADCA=45°,ᑣEK=EL,756"FEK:DEL,2DE=FE,ᓽ956DEFG*(2)ᵫ4CDG=NADE=90஺-4CCE,CD=AD,GD=ED,56^CDG:"ADE,;CG=4E,ᑣCE+CG=4C<7᪷>?@ᳮABACḄᓽ9*(3)ᑖDEFGHN/WE=30஺(Fᙠ8cᐜA;/DEC=4WE+DAC=75°,IUNCEF=/.DEF-Z.CED=15°,ᓽ9᪷>JKᑁKMᳮABNEFCḄNᦪ*NCDE=30஺(FᙠBCḄᐜA;N4ED=4CDE+ADCA=75",IiPNCEF=18(T-NDEF—R4ED=15஺ᓽ9᪷>JKḄH'᜜KTUVWXYḄD'ᑁKḄMAB4EFCḄNᦪ.(⚪[ὃ]ḄᑨUឋ`ஹᐰTJKḄᑨUឋ`ஹ?@ᳮஹJKᑁKMᳮcᐸefgcᦪhᔠUᑖjkfᦪlmnḄoᵨTqrUstᙢ3Bᡠ◤⌕Ḅxy⚪Ḅᐵ{.|18⚓ᐳ18⚓