一元二次方程练习题及答案

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昌江中学九年级数学（一元二次方程）复习题时间 班级 姓名一、选择题（共8题，每题有四个选项，其中只有一项符合题意。每题 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，常数项为零的是（）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化为（x+a） 2=b的形式，正确的是（）A.2A 3 )x- =16; B.I 22； C331x- =-; D.以上都不对<4 /164 .关于x的一元二次方程（a-1 ）x2+x + a2-1=0的一个根是0,则a值为（）A 1 B、1C 、1 或1 D 、125 .已知三角形两边长分别为2和9,第三边的长为二次方程x2-14x+48=0的一根，则这个三角形的周长为（）A.11B.17C.17 或 19D.196 .已知一个直角三角形的两条直角边的长恰好是方程2x2-8x + 7 = 0的两个根，则这个直角三角形的斜边长是（）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 .若关于y的一元二次方程ky2-4y-3=3y+4有实根，则k的取值范围是（）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,则下列说中，正确的是()(A)方程两根和是1(B)方程两根积是2(C)方程两根和是-1(D

22、)方程两根积比两根和大210 .某超市一月份的营业额为200万元，已知第一季度的总营业额共 1000万元，如果平均每月增长率为x,则由题意列方程应为()A.200(1+x) 2=1000B.200+200 X2x=1000C.200+200X 3x=10 00D.2001+(1+x)+(1+x)2=1000二、填空题:(每小题4分，共20分)11 .用 法解方程3(x-2) 2=2x-4比较简便.12 .如果2x2+1与4x2-2x-5互为相反数,则x的值为.13 . x2 -3x += (x-)214 .若一元二次方程 ax2+bx+c=0(a * 0)有一个根为-1,则a、b、c的关系是1

23、5 .已知方程 3ax2-bx-1=0 和 ax2+2bx-5=0,有共同的根-1,贝U a=, b=.16 .一元二次方程x2-3x-1=0与x2-x+3=0的所有实数根的和等于 .17 .已知3- 72是方程x2+mx+7=0的一个根，则m=另一根为18 .已知两数的积是12,这两数的平方和是25,以这两数为根的一元二次方程是._1.±19 .已知Xi, x2是方程x2-2x-1 = 0的两个根，贝U x1 %等于.20 .关于x的二次方程x2 + mx + n = 0有两个相等实根，则符合条件的一组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的实数值可以是 m = , n= .三、用适当方法解方程：（每小题5分，共10分）如（3 - x）2 x2 = 522.x2 2 3x 3= 0四、列方程解应用题：（每小题7分，共21分）23.某电视机厂计划用两年的时间把某种型号的电视机的成本降低36%,若每年下降的百分数相同，求这个百分数.24.如图所示，在宽为203 长为32m的矩形耕地上，修筑同样宽的三条道 路，（互相垂直），把耕地分成大小不等的六块试验田，要使试验田的面积为570n2,道路应为多宽？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 .某商场销售一批名牌衬衫，平均每天可售出20件，每件赢利40元，为了扩大销售，增加赢利，尽快减少库存，商场决定采取适当的降价措施，经调查发现，如果每件衬衫每降价1元，商场平均每天可多售出2件。求:(1)若商场平均每天要赢利1200元，每件衬衫应降价多少元？( 2)每件衬衫降价多少元时，商场平均每天赢利最多？26 .解答题(本题9分)已知关于x的方程x2+2(m-2)x + m2+4 = 0两根的平方和比两根的积大 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一元二次方程复习测试题参考答案 一、选择题:1、B 2、D 3、C 4、B6、B 7、A 8、B 9、C10、D二、填空题：11、提公因式 12-3或113 、 9 , 9 14 、 b=a+c 15 、 1 , -24216、3 17、-6 , 3+应18、x2-7x+12=0 或 x2+7x+12=0 19、-220、2 , 1 （答案不唯一，只要符合题意即可）三、用适当方法解方程: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、列方程解应用题：23、解：设每年降低X,则有(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：设道路宽为 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：道路应宽1m25、解：设每件衬衫应降价 x元。s u d i d I 9a s i gat tsnIgeve g

53、siis iies c .ci.c 1 ict cai e c e.iica rgiel ecas ites c esc ts ia i i -e ct-t s s.isedeltetigls tes c ceisic i e-egt e .一dve tdei.i te c . cnin G e l Sc'seei i eg du des ye g f eeielse c tevl e s is its . ceisic td.i i t iiI 8t avigeels ils ies 一.gs t gs l -i g s eaig t g ea ejai 1eaclcieaesiit

54、 exitai tfiga g e. ejaagae eas ae msi wrvaiuieastaie taev - s.e ev.ictt tk tayf a t s cs sgauld iid 1111at e l. . 一 . .s e ai d egetis u il aaisiig l. _g f- t一2t siaile gefs tepromotetheextensionofstrictlyadministeringthepartygrass-roots,butalsotheeducationalpracticeofthemasslineofthepartyand"t

55、hree-t hree"speciale ducationresults achieved furt herinherited a nd expanded. To realize "twoa" learningeducationisanecessary sol ution t o the present pr oblems ofpartyconstruction.Strengthen problemconsciousness a nd i nsisted onproblem -orie nted, isful lofstrictlyadmi nistering t

56、 he partysince the party's18a distinctive feature,asuccessfulexperience.SecretaryWang noted that somepartymembersstillhave politicalaw areness,la ck ofpoli ticalresponsibi lity issues,partyawarenessand consci ousness ofthe probl embeliefdoes not really believe,slimdoesnota ctually fixpr oblems,outspoken,a ndjump onthe asse ssment oftheparty's poli cies,a nd soon. Bi Li