中考数学基础过关复习第一章数与式第6课时因式分解课件

第6课时因式分解第6课时因式分解中考考什么中考考什么A(a+3)(a-3)a(b+2)(a+b)21.(2017·北部湾模拟)多项式x2-4分解因式的结果是（）A.（x+2）（x-2）B.（x-2）2C.（x+4）（x-4）D.x（x-4）2.(2017·钦州一模)分解因式：a2+2ab+b2=

.3.（2016·南宁）分解因式：a2-9=

.4.（2016·钦州）分解因式：ab+2a=.A(a+3)(a-3)a(b+2)(a+b)21.(2017核心考点解读核心考点解读把一个多项式化为几个整式的

的形式，这样的式子变形叫做这个多项式的因式分解，也叫做把这个多项式分解因式.

因式分解积考点1把一个多项式化为几个整式的

因式分解的基本方法1.提公因式法：如果多项式的各项有公因式，可以把这个公因式提取出来，将多项式写成公因式与另一个因式的乘积的形式，这种分解因式的方法叫做提公因式法.pa+pb+pc=p(a+b+c).考点2因式分解的基本方法1.提公因式法2.公式法（1）两个数的平方差，等于这两个数的和与这两个数的差的积.a2-b2=

.(2)两个数的平方和加上（或减去）这两个数的积的2倍，等于这两个数的和（或差）的平方.a2+2ab+b2=

;a2-2ab+b2=

.(a+b)(a-b)(a+b)2(a-b)22.公式法(a+b)(a-b)(a+b)2(a-b)2x2+（p+q）x+pq=（x+p）（x+q）．十字相乘法：x2+（p+q）x+pq=（x+p）（x+q）怎么考怎么考1．下列各式由左到右的变形中，属于分解因式的是（

）

A．a（x+y）=ax+ay B．x2－4x+4=x（x－4）+4 C．10x2－5x=5x（2x－1） D．x2－16+6x＝（x+4）（x－4）+6x

C焦点1因式分解的概念1．下列各式由左到右的变形中，属于分解因式的是（ ）C焦点1.下列各式由左边到右边的变形中，属于因式分解的是（）A.a(x+y)=ax+ayB.x2-4x+4=x(x-4)+4C.10x2-5x=5x(2x-1)D.x2-16+6x=(x+4)(x-4)+6xC对应训练1.下列各式由左边到右边的变形中，属于因式分解的是（）［命题规律］主要考查分解因式的概念，常以选择题形式呈现.［方法指导］因式分解是把一个多项式分解成几个整式乘积的形式，注意：①分解的是多项式；②整式；③积.［命题规律］主要考查分解因式的概念，常以选择题形式呈现.焦点2因式分解样题2

分解因式：ax+ay=

.a（x+y）［解析］观察等式的左边，提取公因式a即可求得答案.焦点2焦点2因式分解a（x+y）［解析］观察等式的左边，变式训练2.（2016·百色）分解因式：16-x2=（）A.（4-x）（4+x）B.（x-4）（x+4）C.（8+x）（8-x）D.（4-x）23.(2016·梧州)分解因式：2x2-2=（）A.2（x2-1）B.2（x2+1）C.2（x-1）2D.2（x+1）（x-1）AD变式训练AD［命题规律］考查分解因式的意义与两种基本的分解因式的方法.以选择题和填空题呈现，题目常以提公因式法和公式法结合的分解因式为主.［方法指导］（1）pa+pb+pc=p(a+b+c);（2）a2-b2=(a+b)(a-b);（3）a2+2ab+b2=(a+b)2,a2-2ab+b2=(a-b)2.［命题规律］考查分解因式的意义与两种基本的分解因式的方法.以补充练习补充练习

1．分解因式：2a2－6a=

．2．下列分解因式正确的是（B）A．3x2-6x=x（3x-6） B．-a2+b2=（b+a）（b-a）C．4x2-y2=（4x+y）（4x-y） D．4x2-2xy+y2=（2x-y）23．分解因式：2a2－8=

．4．分解因式：

3a2－12ab+12b2=

．2a（a－3）

2（a+2）（a－2）

3（a－2b）2

2a（a－3）2（a+2）（a－2）3（a－2b）27.下列多项式中，能用提公因式法分解因式的是()A.x2-yB.x2+2x

C.x2+y2

D.x2-xy+y2

5.分解因式：3x2-3=

.6.分解因式：X2+2xy+y2-4=

.3(x+1)(x-1)(x+y+2)(x+y-2)B8.分解因式：a2-4a+4=

.

(a-2)27.下列多项式中，能用提公因式法分解因式的是()59.分解因式：a3+2a2+a=

.10.将下列式子因式分解x-x2-y+y2=

.a(a+1)2(x-y)(1-x-y)9.分解因式：a3+2a2+a=.111.关于x的一元二次方程x2+bx+c=0的两根为x1＝1，x2＝2，则x2+bx+c分解因式的结果为：

.12.分解因式：x2-4y2+x-2y=

.

(x-2y)(1+x+2y)（x-1）(x-2)11.关于x的一元二次方程x2+bx+c=012.分解因式：

一、完形填空(共15小题；每小题1分，满分15分)阅读下面短文，掌握其大意，然后从每题所给的A、B、C、D四个选项中选出最佳选项。Lifeisfulloftheunexpected.__1__acoldwinterafternoon，amansawanoldladystandingbyherexpensivecarandclearlysheneededhelp.Sohestoppedand__2__hisoldtruck.“Ishegoingtohurtme?Hedoesn'tlooksafe，”theoldladywas__3__．(B)1.A.InB．OnC．AtD．Under(D)2.A.wentoffB．turnedoffC．tookoffD．gotoff(C)3.A.gladB．excitedC．worriedD．surprised

(B)1.A.InB．OnC．AtD．UnThemancouldseethatshewasafraid，sohesaidinhisfriendliest__4__，“I'mheretohelpyou，madam.Whydon'tyou__5__inthecarwhereit'swarm？__6__，mynameisTedJohnson.”Tedquicklyfixedthecarandtheladythankedhim.Thensheasked__7__sheshouldpayhim.(A)4.A.voiceB．soundC．noiseD．look(A)5.A.waitB．towaitC．waitedD．waits(D)6.A.InawayB．OnmywayC．UnderthewayD．Bytheway(B)7.A.howmanyB．howmuchC．howfarD．howoftenThemancouldseethatsheButTedwanted__8__money.Hewasjustgivingahandtosomeoneintrouble.__9__wasnormalforhimtodosuchathinglikethat.Hesaid，“Ifyoureallywanttorepay(报答)me，nexttimeyouseesomeoneinneed，thinkofmeandhelpthem.”(B)8.A.notB．noC．someD．any(C)9.A.ThisB．ThatC．ItD．TheyButTedwanted__8__money.HAftersayinggoodbye，theladycontinueddowntheroaduntilshereachedasmall__10__whereshedecidedtostopforsomethingtoeat.Astheprettywaitresstookherorder，theladynoticedshewas__11__eightmonthspregnant(怀孕)．Thewaitresslookedtiredandweak，__12__shewasverykind.Astheladywasgoingtopaythe$10bill，sherememberedTed'swords.(A)10.A.restaurantB．bookstoreC．cinemaD．library(C)11.A.mostlyB．hardlyC．nearlyD．seldom(B)12.A.soB．butC．orD．thoughAftersayinggoodbye，thelaAftertheladywasgone，thewaitresssawasmallnoteonthetable.Itsaid，“SomebodyoncehelpedmethewayI'mhelpingyou.Continuebeingkindtootherpeople.”Underthenotewerefive__13__dollars.Thewaitresswas__14__excitedthatshecalledherhusbandtotellhimthenews，“Ted…TedJohnsonmydear…you'renotgoingtobelieve__15__justhappened…”(A)13.A.hundredB．hundredsC．hundredofD．hundredsof(D)14.A.tooB．veryC．suchD．so(C)15.A.howB．whenC．whatD．whyAftertheladywasgone，the二、阅读理解(共15小题；每小题2分，满分30分)阅读下面四篇短文，从每题所给的A、B、C、D四个选项中选出最佳选项。A(2017广东中考改编)二、阅读理解(共15小题；每小题2分，满分30分)中考数学基础过关复习第一章数与式第6课时因式分解课件(C)16.TheWorldPoetryDayison________．A．August28thB．March3rdC．March21stD．August28th(D)17.ThepurposeoftheWorldPoetryDayis________．A．toencouragetheBritishtowritepoemsB．toteachchildrenhowtoreadandwritepoemsC．toraisemoneyforthepoetsfromallovertheworldD．tohelppeopletoread，writeandteachpoemsbetter(C)16.TheWorldPoetryDayi(A)18.TherulesforthecompetitionincludethefollowingEXCEPT________．A．thatpoetscanwritepoemsinanylanguageB．thatpoetsmustusetheirunpublishedpoemsC．thatpoemscan'tbewrittenonthesubjectofviolenceordrugsD．thatpoemscan'tbetakenbackafterthecompetition(A)18.TherulesforthecompBSportscanhelpyoukeepfitandclosetonature.However，whetheryouareonthemountains，inthewaves，oronthegrassland，youshouldrealizethatsportyouchoosemighthavegreatinfluenceontheenvironment.BSomesportsareresource­hungry．Golf，asyoumayknow，eatsupnotonlylargeareasofcountryside，butalsolotsofwater.Besides，hugeamountsofenergyareusedtokeepitscourses(球场)ingoodcondition.Thiscausesmajorenvironmentalchanges.Forexample，inthedryplacesofPortugalandSpain，golfisoftenheldresponsiblefor(为……承担责任)seriouswatershortage(短缺)insomelocalareas.Somesportsareresource­huTherearemanyenvironment­friendlysports.Powerwalkingisoneofthemthatyoucouldtakeuptoday.Youdon'tneedanyspecialequipmentexceptagoodpairofshoes，andyoudon'thavetoworryaboutresourcesandyourpurse.Simpleandfree，powerwalkingcanalsohelpyoustayhealthy.Ifyouwalkregularly，itwillbegoodforyourheart.Expertssaythat20minutesofpowerwalkingdailycanmakeyoufeellessanxious，sleepwellandkeepthin.Therearemanyenvironment­Whateversportyoutakeup，youcanmakeitgreenerthanbyusingenvironment­friendlyequipmentandbuyingproductsmadefromrecycledmaterials.Butthefinalgoalshouldbe“greengyms”．Theyarebetterreplacements(替代)fortraditionalhealthclubsandmodernsportscenters.Membersofgreengymsplaysportsoutdoors，inthecountrysideorotheropenspaces.Thereisnospecialrequirementforyoutostartyourmembership(会员身份)．Andbestofall，it'sfree.Whateversportyoutakeup，(A)19.Whichoffollowingdoestheauthormostprobablysupportaccordingtothepassage?A．Bicyclingaroundthelake.B．Carracingontheroad.C．Playingbasketballinagym.D．Swimminginasportscentre.(D)20.Whatdoestheunderlinedphrase“resource­hungry”inthispassagemeaninChinese?A．广为流行的B．亲近自然的C．低成本的D．耗费资源的(A)19.Whichoffollowingdoe(C)21.Theauthorusespowerwalkingasanexamplemainlybecause________．A．itisanoutdoorsportB．itislovedbymanypeopleC．itusesfewerrecoursesD．itissupportedbyexperts(B)22.Theauthorwritesthepassageto________．A．showusdisadvantagesofgolfB．urgeustotakepartingreensportsC．explainthemajorsportsinfluenceofpopularsportsD．discussdifferentkindsofenvironment­friendlysport(C)21.TheauthorusespowerCLaoShewroteTeahousein1957.TheplayshowstheaudiencelifeinChinabetween1898and1945.IttakesplaceinateahouseinoldBeijingandittellsusthestoryofWangLifaandhiscustomers.Itasksustoseetheteahouseasthecentreoftheneighbourhood.Finally，itsaysgoodbyetooldBeijinganditspeople.CThestorystartsin1898duringtheQingDynasty.Itcontinuesin1916，andfinally，itbringstheaudiencetotheendoftheAnti­JapaneseWarin1945.Afterthewar，Wanglosestheteahouseandhedies.LaoShewasborninBeijingin1899.HisparentssenthimtotheTeacher'sSchoolinBeijingandhelearnedtoteach.From1924to1929hetaughtChinesetotheEnglishinLondon.Hewrotemanyplays，novelsandshortstories.Hewasnameda“People'sArtist”anda“GreatMasterofLanguage”．HewasoneofthegreatestChinesewritersofthe20thcentury.Thestorystartsin1898duInLaoShe'sTeahousetoday，waitersbringteatothecustomersandsellthemdeliciousChinesefood.IfyoulikeBeijingOpera，folkmusic，acrobaticsormagicshows，youcanenjoythemintheteahouse.LaoShe'sTeahousegivesawonderfulwelcometoeveryonefromChinaandfromallovertheworld.InLaoShe'sTeahousetoday(B)23.What'sthemainideaofParagraph4?A．LaoShe.B．LaoShe'sTeahouse.C．ThestoryofTeahouse.D．TheplayTeahouse.(D)24.HowmanyyearsoflifeinChinaisshownintheplayTeahouse?A．57years.B．45years.C．98years.D．47years.(B)23.What'sthemainideao(A)25.LaoShewasallofthefollowingexcept________．A．abossofTeahouseB．aPeople'sArtistC．aGreatMasterofLanguageD．oneofthegreatestChinesewritersofthe20thcentury(C)26.WhowerewelcometoLaoShe'sTeahousetoday?A．OnlyChinesecustomers.B．Onlyforeigncustomers.C．Everycustomerfromhomeandabroad.D．OnlyBeijingOperaaudience.(A)25.LaoShewasalloftheDSpecialBridgesHelpAnimalsCrosstheRoad

ReportedbySheilaCarrickWhydidthechickencrosstheroad?Togettotheotherside.Mostpeopleknowthisjoke.Butrecently，somepeoplehavebeenmuchmoreworriedabouthowthegrizzlybear(灰熊)andmountainlioncancrosstheroad.D“MillionsofanimalsdieeachyearonUSroads，”theFederalHighwayAdministrationreports.Infact，onlyabout80ocelots，anendangeredwildcat，existintheUStoday.Themainreason?Roadkill.“Ecopassages(生态通道)”mayhelpanimalscrosstheroadwithoutbeinghitbycars.Theyarepathsbothoverandunderroads.“Theseecopassagescanbeextremelyuseful，sothatwildlifecanavoidroadaccidents，”saidJodiHiltyoftheWildlifeProtectionSociety.“MillionsofanimalsdieeaButdoanimalsactuallyusetheecopassages?Theanswerisyes.PaulBeierofNorthernArizonaUniversityfoundfootmarksleftbymountainlionsonanecopassagethatwentunderahighway.Thisshowedthatthelionsusedthepassage.Buildersofecopassagestrytomakethemlooklikeanaturalpartofanareabyplantingtreesonandaroundthem.Animalsseemtobecatchingon.Animalsasdifferentassalamanders(火蜥蜴)andgrizzlybearsareusingthebridgesandunderpasses.Thenexttimeyouvisitaparkordrivethroughanareawithalotofwildlife，lookaround.Youmightseeananimaloverpass!Butdoanimalsactuallyuse(D)27.Thewriterusestheexampleof“ocelots”toshowthat________．A．wildanimalshavebecomemoredangerousB．thedrivingconditionshaveimprovedgreatlyC．themeasureforprotectingwildlifefailstoworkD．anincreasingnumberofanimalsarekilledinroadaccidents(D)27.Thewriterusestheex(D)28.Fromthepassage，weknowanecopassageis________．A．anundergroundpathforcarsB．afencebuiltforthesafetyoftheareaC．abridgeforanimalstogetoverariverD．apathforanimalstocrosstheroad(D)28.Fromthepassage，wekn(B)29.Whenthewritersaysthat“Animalsseemtobecatchingon”，hemeans________．A．animalsbegintorealizethedangersontheroadB．animalsbegintolearntouseecopassagesC．animalsarecrossingtheroadingroupsD．animalsareincreasinginnumber(B)29.Whenthewritersayst(D)30.Thewriterasksvisitorsanddriverstolookaroundwhentravellingbecause________．A．wildanimalsmayattackcarsB．wildanimalsmayjamtheroadC．theymayseewildanimalsintheparkD．theymayseewildanimalsonecopassages(D)30.Thewriterasksvisito三、词汇运用(共15小题；每小题1分，满分15分)A．用方框中所给词语的适当形式填空。每词限用一次。31．MrLihasmadea__decision__totraveltoBeijing.32．Theschool__provides__thestudentswithdeliciousfoodeveryday.33．Hejustsat__in__silence__anddidn'tsayanywords.34．Ihavebeentoseveral__European__countries，suchasEnglandandFrance.35．Youcan'tgo__across__thestreetwhenthetrafficlightsturnred.三、词汇运用(共15小题；每小题1分，满分15分)B．根据短文内容和所给中文提示，在空白处写出单词的正确形式。每空限填一词。Itis8：30amattheChengduResearchBase.LinWei，apandakeepers，ispreparingthemilkforthebabypandas'36.__breakfast__(早餐)．At9：00am，shefindsthatmostofthebabiesarealready37.__awake__(醒着的)andhungry.Whenthebabiesseethekeepers，theyrunoverwithexcitement，andsomeofthemeven38.__walk__(行走)intotheirfriendsandfallover!They'resocuteandlovely.LinWeitakescareofthemlikethey'reher39.__own__(自己的)babies.Shewashes，feedsandplayswiththemeveryday.B．根据短文内容和所给中文提示，在空白处写出单词的正确形式。Pandasdonothavemanybabies，maybeonlyoneeverytwoyears.Thebabiesoften40.__die__(死亡)fromillnessesanddonotliveverylong.Adultpandasspendmorethan12hoursadayeatingabout10kilosofbamboo.Manyyearsago，therewerealotmorebambooforestsandpandasinChina.Butnowpandasareingreat41.__danger__(危险)．Peoplecutdownmanybambootreessotheyarelosingtheirhomes.Thereareabout1，59042.__wild__(野生的)pandaslivingintheforestsinSichuan，ShaanxiandGansuprovinces.Another200orsoliveinzoosorresearchcentresinChinaandothercountries.PandasdonothavemanybabIt'sa43.__pity__(遗憾)thatmanypeopledon'tknowthat.SothegovernmenthassetupaneducationprogrammeinChengdu.Itteacheschildrenincitiesaboutpandas，andtellsthemaboutthe44.__importance__(重要性)ofsavingthepandas.Butteachingchildrenisonewaytohelp45.__protect__(保护)environmentandsavepandas.TheChinesegovernmentisalsoplantingmorebambootreessotherewillbemoreforestsforpandastolivein.Weallhopethatinthefuturetherewillbealotmorepandasthannow.It'sa43.__pity__(遗憾)that四、语法填空(共10小题；每小题1分，满分10分)阅读下面短文，在空白处填入一个适当的词，或填入括号中所给单词的正确形式。Somepeoplestillliveintheirhometown.However，othersmayonlyvisit46.__it__onceortwiceayear.MillionsofChineseleavethecountryside47.__to__search__(search)forworkinthecities.AmongtheseisHuaXing.He48.__has__lived__(live)inWenzhouforthelast13years.Withahardjob49.__in__afactory，heseldomvisitshishometown.“Ihaven'tbeenback50.__for__threeyears.It's

ashame，”hesays.四、语法填空(共10小题；每小题1分，满分10分)51．__Developments__(develop)havebeengoodinHuaXing'shometownsince2002，forexample，newroads52.__have__appeared__(appear)．Anewschool53.__has__been__built__(build)．However，somethingswillneverchangeinhishometown.Thebigoldtreeisstillbesidetheplayground.Childreninhistime54.__usually__(usual)likedtoplaytogetherunderit.Itwas55.__such__happychildhood.51．__Developments__(develo五、(2017邵阳中考)任务型阅读(共5小题；每小题1分，满分5分)

阅读下列短文，在空白处(56—60)填入与短文内容相符的信息，完成阅读摘记。MaciekCzastkawasborninLodz，Poland.HecametoChinaseveralyearsago.Sofar，hehasbeenworkinginChengduforthreeyears.五、(2017邵阳中考)任务型阅读(共5小题；每小题1分，“TheBeltandRoadInitiative(一带一路的倡议)ismeaningful，”hesaid.“Thankstoit，weareofferedmorechances.”ThemostpowerfulsupportforChengdutothrive(兴盛)alongtheBeltandRoadistheChengdu­Europeexpressrailway(高速铁路)．It