最新沪科版八年级数学下?2017-2018学年安徽省滁州市八年级下期末数学试卷 - 百度文库

12xx1=x1 2x+12x6=1

1ȡʽx1һɵã 2һʽʽɵã 𡿽⣺12xx1=x1 2xx1x1=0 x12x1=0 x1=02x1=0 ãx=1x=

2ԭһʽΪ2x24x7=0 a=2b=4c=7

=16427=720 x=

=

⿼˽һԪη̩ʽֽⷨ䷽ԼʽոֽⷨǽⱾĹؼ

ġ⹲2С⣬ÿС8֣16֣

178֣ͼС֪ѧУ˵ĸ߶ȣ˶AӴB󻹶2ףֱʹ¶˸պýӴC¶˵¶˵ľΪ6ףС˵ĸ߶AB

ΪˡӡùֱΣ˵ĸ߶ΪxףӵijΪx+2ףݹɶ˵ĸ߶ȣ 𡿽⣺˵ĸ߶ΪxףӵijΪx+2ף ݹɶɵãx2+62=x+22 ãx=8

˵ĸ߶Ϊ8ף

⿼ѧùɶʵĹؼδ֪ʾ߳ȣùɶ

188֣?ABCDУBCDƽBAӳ߽ڵECEADF

1֤AE=AF

2BHCEڵHD=50㣬CBHĶ

1֤AE=AFֻҪ֤E=AFEɣ 2취BCHɽ⣻

𡿽⣺1ıABCDƽıΣ ADBCBECD

AFE=BCEE=DCE ߡBCE=DCE AFE=E AE=AF

2ADBC

D+BCD=180㣬 ߡD=50㣬 BCD=130㣬 ECƽ֡BCD BCE=BCD=65㣬 BHCE

CBH=90㩁65=25

⿼ƽıεʡƽߵĶԼεжʣĹؼѧ֪ʶ⣬пͣ

塢⹲2С⣬ÿС10֣20)

1910֣֪xķx2m+1x+2m1=0 1֤mȡֵʱʵ

2һ߳Ϊ4ǡǴ˷̵ĸε߳

1ݷ̵ϵϸбʽɵó=m320ɴ˼֤mȡֵʵ 2Ϊ4͵ױ߳Ϊ4ֱɵã

𡿽⣺1֤ߡ=[m+1]242m1=m26m+9=m320

mȡֵʵ

2Ϊ4x=4ԭ̣ã164m+1+2m1=0 ãm=5

ԭΪx26x+8=0 ãx1=2x2=4

ε߳Ϊ244

ױ߳Ϊ4˷ʵ =0m=3 ʱΪx24x+4=0 ãx1=x2=2

2+2=4ܹΣȥ ߳Ϊ42

⿼˸бʽ߹ϵεԼһԪη̣Ĺؼǣ1μǡ0ʱʵ2x=4mֵ

2010֣סͬѧһϲԣֱ׼涨6ϣ6Ϊϸ9ϣ9Ϊ㣬ͬѧIJԳɼ± ɼ 4 飨ˣ 飨ˣ ֽͬѧIJԳɼƳ²ͳͼ

1 1 4 5 2 2 1 5 2 6 5 7 2 8 1 9 4

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