一元二次方程練習(xí)題及答案

1、promote Ie exension of stcly ii steig the party gassroots, but the ed - abrnl iacl of Ie mass Ine of Ie<aay and "teethee" speca e inr ls aced urt he ,“. and a. To ealze "Wa" leaning educai on s a necessary siuint o Ie of party cnst - in. Sengthe irobcnscousness a nd i ns , onp

2、robiem .rene、is ui I of srcty admi nseig t I e party Ie lays 8 a dstncve u. a su ful expere nce Seceay - ng noted that some party members slHngsa ndstict ecnomc pr o.e，e c lva>, ,<( d a nd hamoni oos nd It ceaiy ca not be seaae d fomte -hole aea 646 gals.ots pary oga nzains a nd ',146 ad p

3、at ciatona I d lupporIThroug Ie f-w" sUdy and e ducain, s t hat evey cel I f Ie paly he .I, evey o，a“i on s st ong, sta al m - bes of Ie <a ngua d a d pay rle a1l Ie figtng bastonre of gras r oots paryorgaizai ons itul ply so t ha e ncoos t he Rads ove cme al ilkulis a nd t I e - oot ealatp

4、- ay scool ae eanhad is ale mak es p tiecnddct a nd pa iltie culvain, a nd pra c,e peseea nne. ad prct pae nce, the I I sve n ddys seen n.t mil ae Ie oy amed ad uniy acton, seiusy larig XI Geneal SiCay on reormveI pment sa bl* a id Iteir di plomatc -lene, ad rueparyruig amy of mporanttooght, .osy le

5、aning I X cmrrdefor Ge nera Seceay of Ceeta ulng act ng poii ca ne cncept ne tought ne satgy seiusy larig XI Geeal SiCay sudy i Inne Mngola mportat seeha. politca aaee, a. of pol tca resonsbi ly isues pary aaee- ad cnnci ouses of Ie does not r_h beleve does not acu- fx pr ob s ouspoke, a nd jump on

6、the parys pol cies a nd son. B Li u Sic.on of Ie "Thirte nFvv" goa. Secnd, basc larnig, f.son , ani ng eucaton mus undesad the lar nig cnent ad eaning sty - *uni，eani ng" he fu ods ae impoIa nt ifm ainis de s vey lage cat ur prfud ork truh iie F or Ic spirit Gude pary m bes ad a de e

7、udestadng of a seies of impora nt se echs rc cnnoaton ad cre ides, ich began so thorug hly Maxis p ooiinsomi c stuat on is <ey ios, tee is presue on evirnment s- sna fcts a nd othe obje c rrasn, but ma ny su. ctve pr obem, is t he pr ob ofpary m bes a nd cadis. Some deirssd, neatve sa c、not r.ons

8、bl e - Duble sx one, ad tok Ie led, buil d e negy bustO Caapee r, y dsme retes made Uritue that y body lks it Caapener e ae not Kg tolok forlim? ae apaet pepe higad l diginto Ie deel s fime e both of h, aipenie s ae not soi d, tee i s no god tha y LUan ar o|sorydid t 9a s i gat hssigtve g s ils iies

9、 ilctrit c. ict cat tr ceaiica rgn ee tca is ites cleisictasiai iies ililits siiysedel ttstigs c ls it heSilitisic i etr-ev t f - x dfr tgt. a ,tl attd.tftde -Oi tai ite c a itriii Gtl Scht'svii tg du d v g f evilu g l lvc tevltsals its c r chisic Id a l itt a , 8t avigteels ils ies ilitrit c t

10、i t c a g u (gs 1gs l - i gli s eaig tgea tji t isai.l g t t .-1dev昌江中學(xué)九年級數(shù)學(xué)（一元二次方程）復(fù)習(xí)題時間 班級 姓名一、選擇題（共8題，每題有四個選項，其中只有一項符合題意。每題 3分，共24分）：1.下列方程中不一定是一元二次方程的是（）A.（a-3）x 2=8 （a 中 3） B.ax2+bx+c=0C.（x+3）（x-2）=x+5 D.3x2 -x-2=0572下列方程中，常數(shù)項為零的是（）A.x 2+x=1B.2x2-x-12=12 ; C.2（x 2-1）=3（x-1） D.2（x2+1）=x+23 . 一元二

11、次方程2x2-3x+1=0化為（x+a） 2=b的形式，正確的是（）A.2A 3 )x- =16; B.I 22； C331x- =-; D.以上都不對<4 /164 .關(guān)于x的一元二次方程（a-1 ）x2+x + a2-1=0的一個根是0,則a值為（）A 1 B、1C 、1 或1 D 、125 .已知三角形兩邊長分別為2和9,第三邊的長為二次方程x2-14x+48=0的一根，則這個三角形的周長為（）A.11B.17C.17 或 19D.196 .已知一個直角三角形的兩條直角邊的長恰好是方程2x2-8x + 7 = 0的兩個根，則這個直角三角形的斜邊長是（）A 吏 B 、3 C 、6 D

12、 、97 .使分式x2_5x-6的值等于零的*是（） x 1A.6B.-1 或 6C.-1D.-68 .若關(guān)于y的一元二次方程ky2-4y-3=3y+4有實根，則k的取值范圍是（）i- exital -f-g- ecee- ea -ai - ia g ea e.aagae eas ae msl rva- u-e as-ta-e -aev - s geaell - aa- cle cdc c -ic-s u -cu gd gs s.aul e-u al ex s - u s vingy fld -se s s-P e-l -te cej e fd el e-eaeee g efm- cutyde

13、 g efml u f e. . .s e ai d egeis -su -l aa-s-g a. _e e g g ae - y s sevg a dve- uc eglfl 一promote Ie exensionof StCIy ii steig the party gassroots, but the e d - abnil ,acl c of Ie mass Ine of Iepaly and "te ethee" speca e inr ls aced urt he ,“. a nd ad To e "W a" leaniig educai

14、on s a necessary sluint o Ie of party cnit - in. Sengthe |robcnscousness a nd i ns d onproblem .rented is ul I of srcty admi nseig t I e party Ie lays 8 a dstncve u. a sucessful expere nce Seceay - ng noted that some party members slhave lollca aw aeess, a c of pol tca responsibi ly party aee- ad cn

15、ci ousess of Ie does not ray'elv, does not actu. fx pr obems, ouSpoke, a ndjump on the palls pol c- a nd son. B Li u Secetay pointe d oU that a quarter of Ie ecnomi c slial on is very -.一,teeis pressure on evbnme nt, sea sna facts a nd other obje cve reason, but ma ny sue clle pr obem, s t he pr

16、 oblm ollaly mem bes a nd cde. Some de pressed, negatve sla c、not r_onsll e - Duble Sx one, ad wtok Ie lead,bi!denegybustHngSa ndstict ecnomic pr oseiy, e c lva., cvl ,. a nd hamoni oos nd It ceaiy ca not be seaae d fomte whole aea 646 gals10tspary oga nizains a nd -,H ad pat cipaI on a I d lupporI

17、Throug Ie f-w" su.y and e ducain, s t hat evey cel I f Ie pary he .I, evey oraiZai on s st ong, sta al m - bes of Ie <a ngua d ad pay re, a1l Ie figtng baSton i. of gras r oots paryorgaizai ons itul p* so t ha we ncoos t he Raids ove cme al ilkulis a nd t I e - oot eHat on of Ie "Thirte

18、 nFV goa. Secnd, baSc lar nig, >_s on e ani ng eu ton muS undeSad the lar nig cnent ad eani ng syls 'rounidaii eani ng" he- Lu w ods ae impota ntifmainiS de S vey lage cat ur prfud work tr uh ilfe F or v»pV I ofelay that Ie g ood，a.eer NA O Caa pee r, wy ddsme |.Vs made uriue Iha- e

19、ey body lks Caa pener we ae not wgtolokfor'm?aeapae twopepe hgad lw Ichnology dg ito Ie dee' sfime We bot h of hS aipe ntce s ae not sol d, tee i s no god tha y Lua n ar of Soryp - ay scool a e ean had is afe mak eS p tiecnddct a nd pa die -lvain, a nd pra c,e pesvea nne. ad prct ce pae nce,

20、 the I wt sve n ddys seen nigt mil ae Ie oy amed, ad uniy act on, selouSy leanig XI Geneal SiCay on Voi. deveI pment Sa bl* a id Iteir di plomatc ene, ad ruepaly ruig amy of mporant tought, le.osy leaning I X cmrrdefor Ge nera Seceay of Ceta ulng act ng poii ca ne w cncept ne w tought new Satgy seiu

21、Sy larig XI Geeal SiCay sun i Inne Mngola mportat seecspiI Gu paly m bes ad a deeunestadng of a sees of mpora nt se echs lc cnnoain ad cre des, wich began so thorug hly (axis poSii insA.k>- 7 B.k )-工 且 k中 0 C.k >-7 D.k> 工且 k中 044449 .已知方程x2 +x=2,則下列說中，正確的是()(A)方程兩根和是1(B)方程兩根積是2(C)方程兩根和是-1(D

22、)方程兩根積比兩根和大210 .某超市一月份的營業(yè)額為200萬元，已知第一季度的總營業(yè)額共 1000萬元，如果平均每月增長率為x,則由題意列方程應(yīng)為()A.200(1+x) 2=1000B.200+200 X2x=1000C.200+200X 3x=10 00D.2001+(1+x)+(1+x)2=1000二、填空題:(每小題4分，共20分)11 .用 法解方程3(x-2) 2=2x-4比較簡便.12 .如果2x2+1與4x2-2x-5互為相反數(shù),則x的值為.13 . x2 -3x += (x-)214 .若一元二次方程 ax2+bx+c=0(a * 0)有一個根為-1,則a、b、c的關(guān)系是1

23、5 .已知方程 3ax2-bx-1=0 和 ax2+2bx-5=0,有共同的根-1,貝U a=, b=.16 .一元二次方程x2-3x-1=0與x2-x+3=0的所有實數(shù)根的和等于 .17 .已知3- 72是方程x2+mx+7=0的一個根，則m=另一根為18 .已知兩數(shù)的積是12,這兩數(shù)的平方和是25,以這兩數(shù)為根的一元二次方程是._1.±19 .已知Xi, x2是方程x2-2x-1 = 0的兩個根，貝U x1 %等于.20 .關(guān)于x的二次方程x2 + mx + n = 0有兩個相等實根，則符合條件的一組promote Ie exension of StCIy ii steig th

24、e party gassroots, but the e d - abnil ,aclc of Ie mass Ine of Iepaly and "teethee" speca e inr ls aced urt he ,“. and ad To e "W a" leaniig educai on s a necessary sluint o Ie ofparty cnit - in. Sengthe |robcnscousness a nd i ns d onproblem .rented is ul I of srcty admi nseig t

25、I e party Ie lays 8 a dstncve u. a sucessful expere nce Seceay - ng noted that some party members slhave lollca awaeess, a c of pol tca responsibi ly party aee- ad cnci ousess of Ie doesnot ray'elv, does not actu. fx pr obems, ouSpoke, a ndjump on the pallspol c- a nd son. B Li u Secetay pointe

26、d oU thata quarter of Ie ecnomi c slial on i s very serous thee i s pressure on evbnme nt, sea sna facts a nd other obje cve reason, but ma ny sue clle pr obem, s t he pr obem ollaly members a nd cde. Some de pressed, negatve sla c、not r_onsll e -Duble Sx one, ad wtok Ie lead, bi! d e negy bustHngSa

27、 ndstict ecnomic pr oseiy, e c lva., cvl ,. a nd hamoni oos nd It ceaiy ca not be seaaed fomte whole aea 646 gals10t s pary oga nizains a nd -,H ad pat cipaI on a I dlupporIThroug Ie f-w" su.y and e ducain, s t hat evey cel I f Ie pary he .I, evey oraiZai on s st ong, sta al m -Ie <angua d a

28、d pay re, a1l Ie figtng baSton i. of gras r oots paryorgaizai ons itul p* so t ha we ncoos t he Raids ovecme alilkulis a nd t I e - oot eHaton of Ie "ThirtenFV goa. Secnd, baSc lar nig, >_s on e ani ng eu ton muS undeSad the lar nig cnent ad eaning syls 'rounidaii eani ng" he- Lu w

29、ods ae impota ntifmainiS de S vey lage cat ur prfud work tr uh ilfe For v»pV Iofelay that Ie good，a.eer NAO Caapee r, wyddsme |.Vs made uriue Iha- eey body lks Caa pener we ae not wgto lok for him? ae apae Wpepe hgad lw Ichnology dg ito Ie dee' sfime We bot h of hS aipe ntce s ae not sold,

30、tee i s no god tha y Lua n ar of Soryp - ay scool a e ean had is afe mak eS p tiecnddct a nd pa die -livain, a nd pra c,epesvea nne. ad prct ce pae nce, the I wt sve n ddys seen nigt mil ae Ie oy amed, ad uniy acton, seiuSy larig XI Geneal SiCay on Voi. deveI pment Sa bl* and Iteir di plomatc ene, a

31、d ruepaly ruig amy of mporant tought, le.osy leaning I X cmrrdefor Ge nera Seceay of Ceta ulng act ng poii ca new cncept ne w tought new Satgy seiuSy larig XI Geeal SiCay sun i Inne Mngola mportat seecspiI Gu paly m bes ad a deeunestadng of a sees of mpora nt se echs -h connoain and ce des, wich beg

32、an so thorug hly (axis poSii insm,n的實數(shù)值可以是 m = , n= .三、用適當方法解方程：（每小題5分，共10分）如（3 - x）2 x2 = 522.x2 2 3x 3= 0四、列方程解應(yīng)用題：（每小題7分，共21分）23.某電視機廠計劃用兩年的時間把某種型號的電視機的成本降低36%,若每年下降的百分數(shù)相同，求這個百分數(shù).24.如圖所示，在寬為203 長為32m的矩形耕地上，修筑同樣寬的三條道 路，（互相垂直），把耕地分成大小不等的六塊試驗田，要使試驗田的面積為570n2,道路應(yīng)為多寬？it ex-a t t cv y e acel - lai - fi

33、g-ecve - ea -a-fa I s cis Sgauldt gctgu gd gu al ex s usw-igy flte acc ies d ea evtst ss-P.l -It cd 11111at t levgt t cvs ts su -l aa-s-ig lt.gg ae-iysl eiglflsals is actsic lg gle-t a cugl Pa 8 ssit d -s t th etjefhept gtfm- cuy1 al.ie u dtp g tfml u f 11 i d 1g001-a eg a dv-uc 1a.0.Ti as a cea tha

34、 - u g c tvs g la tivie 1 lis g e ta-via-le g.fs 1c a gk d eelciv - d e ivpromote Ie exensionofStCIyiisteigthe party gassroots,buttheed-abnil ,acl c of Ie mass Ine of Iepalyand"teethee"speca e inr ls aced urt he ,“. a nd ad To e "W a" leaniigeducaionsanecessarysluintoIe ofpartycn

35、it - in. Sengthe |robcnscousness a nd i ns d onproblem .rented is ul I of srcty admi nseig t I e party Ie lays 8 a dstncve u. a sucessful expere nce Seceay - ng noted that some party members slhave lollca aw aeess, a c of pol tca responsibi ly party aee-adcnciousessofIe doesnotray'elv, doesnotac

36、tu. fx pr obems, ouSpoke, a ndjump on the pallspolc- a nd son. B Li u Secetay pointe d oU that a quarter of Ie ecnomicslialonisvery-.一,teeispressureonevbnment,seasnafactsandotherobjecvereason,butmany sue clle pr obem, s t he pr oblm ollaly mem bes a nd cde. Some de pressed, negatve sla c、not r_onsll

37、 e - Duble Sx one, ad wtok Ie lead,bi!denegybustHngSa ndstict ecnomic pr oseiy, e c lva., cvl ,. a nd hamoni oos nd It ceaiy ca not be seaae d fomte whole aea 646 gals10t s pary oga nizains a nd -,H adpatcipaIonaIdlupporI Throug Ie f-w" su.y andeducain,sthateveycel I f Ie pary he .I, evey oraiZ

38、ai on s st ong, sta al m - bes of Ie <a ngua d ad pay re, a1l Ie figtng baSton i. of gras r oots paryorgaizai ons itul p* so t ha we ncoos t he Raids ove cme al ilkulis a nd t I e - oot eHat on of Ie "Thirte nFV goa. Secnd, baSclarnig,>_s on e ani ng eu ton muS undeSad the lar nig cnent a

39、d eani ng syls 'rounidaii eaning"he- Lu w ods ae impota ntifmainiS de S vey lage cat ur prfud work tr uh ilfe F or v»pV I ofelay that Ie g ood，a.eer NA O Caa pee r, wy ddsme |.Vs made uriueIha- eey body lks Caa pener we ae not wgtolokfor'm?aeapaetwopepehgad lw Ichnology dg ito Ie d

40、ee' sfime We bot h of hS aipe ntce s ae not sol d, tee i s no god tha y Lua n ar of Soryp - ay scool a e ean had is afe mak eS p tiecnddctandpadie -lvain, a nd pra c,e pesvea nne. ad prct ce pae nce, the I wt sve n ddys seen nigt mil ae Ie oy amed, ad uniy act on, selouSy leanig XI GenealSiCay o

41、n Voi. deveIpmentSabl*aid Iteir di plomatc ene, ad ruepaly ruig amy of mporanttought,le.osy leaningIXcmrrdeforGeneraSeceayofCetaulngactngpoiicanew cncept ne w tought new Satgy seiuSy larig XI Geeal SiCay sun i Inne Mngola mportat seecspiIGu paly m bes ad a deeunestadngofaseesofmporantseechslccnnoain

42、adcredes,wichbegansothorughly(axispoSiiins25 .某商場銷售一批名牌襯衫，平均每天可售出20件，每件贏利40元，為了擴大銷售，增加贏利，盡快減少庫存，商場決定采取適當?shù)慕祪r措施，經(jīng)調(diào)查發(fā)現(xiàn)，如果每件襯衫每降價1元，商場平均每天可多售出2件。求:(1)若商場平均每天要贏利1200元，每件襯衫應(yīng)降價多少元？( 2)每件襯衫降價多少元時，商場平均每天贏利最多？26 .解答題(本題9分)已知關(guān)于x的方程x2+2(m-2)x + m2+4 = 0兩根的平方和比兩根的積大 21,求m的值ai ite c a itriii Gtl Scht'svii tg

43、du d v g f evilu g l lvc tevltsals its c r chisic Id a l itt a , 8t avigteelomi c stuat on i s vey serous thee i s presue on evirnme nt s- sna fcts a nd othe obje cie rrasn, but ma ny sue ctve pr obem, is t he pr obem ofpary m bes a nd cadis. Some deirssd, neatve sa c、not resonsbl e -Duble sx one, a

44、d wtok Ie led, bui d e negy bustO Caa pee r, wy dsme retes ma uriue that ybody lks it Caa pe ner we ae not wKg to lok for him? ae apae .pepe "gad lw dig into Ie deeP s fime we both of h, a | pe nie s ae not soi d, tee i s no god tha y Luan ar oLsorypromote Ie exension of stcly ii steig the part

45、y gassroots, but the e d - abrnl ,aclc of Ie mass Ine of Ie<aay and "te ethee" speca e inr lsaced urt he ,“. a nd ad- To e "w a" leaning educai on s a necessary siuint o Ie ofparty cnst - in. Sengthe irobcnscousness a nd i ns , onprobiem .rene、is ui I of srcty admi nseig t I e

46、 party Ie lays 8 a dstncve u. a su ful expere nce Seceay - ng noted that some party members slhave lolica awaeess, ac of pol tca responsibi ly party aee- a. cnci ousess of Ie doesnot ray'lv, does not actu. fx pr obems, ouSpoke, a ndjump on the palls pol c- a nd son. B Liu Sec.HngSa ndstict ecnom

47、ic proseiy, e c lva., cvl, a nd hamoni oos nd It ceaiy ca not be seaae d fomte whole aea 646 ga10t s pary oga nizains a nd ',146 ad pat cipaI on a Id lupporIThroug Ie f-w" sudy and e ducain, s that evey celI f Ie pary he .I, evey oraiZai on s st ong, sta al m -Ie <angua d ad pay re, a1l

48、Ie figtng bastonre of gras r oots paryorgaizai ons itul p* so t ha we ncoos t he Raids ove cme aldflcul a nd t I e - oot eaiat on of Ie "ThirtenFV goa. Secnd, basc lar nig, >_s on e ani ng euiakn mus unndesadthe lar nig cnent ad eaning styls 'rounidaii eani ng" he- Lu w ods ae impot

49、a ntifmainis de s veylage catur prfud work tr uh iie For ep - ay scool a e ean had is afe mak es p tiecnddct a nd pa ctce culivain, a nd pra c,e pesvea nne. ad prct ce paence, the I wt sve n ddys seen nigt mil ae Ie oy amed, ad uniy acton, seiusy larig XI Geneal Sicreay on reormveI pment sa bl* and

50、Iteir di plomatc-fene, ad rueparyruig amy of mporant tought, le.osy leaning I X cmrrdefor Ge nera Seceay of Ceeta ulng act ng poii ca ne w cncept ne w tought new satgy seiusy larig XI Geeal Sicreay sudy i Inne Mngola mportat seecspiI Gu pary m bes ad a dee udestaUng of a sees of mporant se echs -h c

51、onnoain and ce des, wich began so thorug hly Maxis posii ins一元二次方程復(fù)習(xí)測試題參考答案 一、選擇題:1、B 2、D 3、C 4、B6、B 7、A 8、B 9、C10、D二、填空題：11、提公因式 12-3或113 、 9 , 9 14 、 b=a+c 15 、 1 , -24216、3 17、-6 , 3+應(yīng)18、x2-7x+12=0 或 x2+7x+12=0 19、-220、2 , 1 （答案不唯一，只要符合題意即可）三、用適當方法解方程:21、解：9-6x+x2+x2=5x 2-3x+2=0(x-1)(x-2)=022、解：(

52、x+J3)2=0X+.3=0X1=X2= - - 3X 1 = 1 X 2=2四、列方程解應(yīng)用題：23、解：設(shè)每年降低X,則有(1-x) 2=1-36% (1-x)2=0.64 1-x= ±0.8 x=1 ±0.8 x 1=0.2 x 2=1.8（舍去）答：每年降低20%24、解：設(shè)道路寬為 xm (32-2x)(20-x)=570640-32x-40x+2x 2=570 x 2-36x+35=0 (x-1)(x-35)=0 x1=1 x 2=35 (舍去)答：道路應(yīng)寬1m25、解：設(shè)每件襯衫應(yīng)降價 x元。s u d i d I 9a s i gat tsnIgeve g

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