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解方程 x÷= 4:x=3:2.4.
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解方程6x﹣5=﹣24.
解方程x2x+3=4x+6
解方程3x+4=x.
解方程. 65%x﹣50%x=12056﹣40%x=28x+x=24.
解方程xx﹣3=4x+6.
解方程:x-4x+3+2+x2-x=4.
解方程4x3x-2=6x-4.
我们规定若关于x的一元一次方程ax=b的解为b﹣a则称该方程为差解方程例如2x=4的解为2且2=4﹣
解方程3x﹣42x+5=x+4
解方程2+x=2x+5.
解方程x﹣32+4xx﹣3=0.
下列解方程的过程中正确的是
x
2
=-2,解方程,得x=±
(x-2)
2
=4,解方程,得x-2=2,x=4
4(x-1)
2
=9,解方程,得4(x-1)=±3,x
1
=
,x
2
=
(2x+3)
2
=25,解方程,得2x+3=±5,x
1
=1,x
2
=-4
理解同解方程的定义再解题1同解方程的定义为如果两个方程的解相同那么这两个方程叫同解方程反之如果两个方
解方程x2-4x-3=0
解方程 40%x=80x+20%x=24.
解方程:x﹣3=4x﹣32
解方程x﹣1x﹣2=x+3x﹣4+20.
解方程或比例.2x+3×0.9=24.7x=24.
解方程6x-5=-24.
阅读下面的解题过程解方程4x-12-104x-1+24=0解把4x-1视为一个整体设4x-1=y则原
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如图所示在xOy平面内存在均匀大小随时间周期性变化的磁场和电场变化规律分别如图乙丙所示规定垂直纸面向里为磁感应强度的正方向沿y轴正方向电场强度为正.在t=0时刻由原点O发射初速度大小为υ0方向沿y轴正方向的带负电粒子.已知u0t0B0粒子的比荷不计粒子的重力. 1t=时求粒子的位置坐标 2若t=5t0时粒子回到原点求0~5t0时间内粒子距x轴的最大距离 3若粒子能够回到原点求满足条件的所有E0值.
如图所示固定的水平光滑金属导轨间距为L左端接有阻值为R的电阻处在方向竖直磁感应强度为B的匀强磁场中质量为m的导体棒与固定弹簧相连放在导轨上导轨与导体棒的电阻均可忽略.初始时刻弹簧恰处于自然长度导体棒具有水平向右的初速度v0.在沿导轨往复运动的过程中导体棒始终与导轨垂直并保持良好接触. 1求初始时刻导体棒受到的安培力. 2若导体棒从初始时刻到速度第一次为零时弹簧的弹性势能为Ep则这一过程中安培力所做的功W1和电阻R上产生的焦耳热Q1分别为多少导体棒往复运动最终将静止于何处从导体棒开始运动直到最终静止的过程中电阻R上产生的焦耳热Q为多少
增加在缺词处加一个漏字符号∧并在其下面写出该加的词. 删除把多余的词用斜线\划掉. 修改在错的词下划一横线并在该词下面写出修改后的词. 注意1.每处错误及其修改均仅限一词2.只允许修改10处多者从第11处起不计分. WhenIturned18lastJulyIdecidedtolearndriving.Mybrothervolunteerstoteachmebuthelackedofpatience.WheneverImadethemistakehewouldgetangrywithme.IfeltsuchdiscouragedthatIwantedtogiveup.BeforeknowingwhatIwasthinkingmyfriendTomencouragedmelearninadrivingschool.IfollowedhisadviceandundertheguidanceofmycoachIregainedconfidence.WithtimegoesonIfounddrivingnotonlyinterestingbutalsoveryeasily.AtlastIpassedthedrivingtestatthefirstattempt.AtthatmomentIgotreallyexcitingandcouldhardlykeepbackmytear.
某同学设计了一个电磁推动加喷气推动的火箭发射模型其工作原理如图所示.竖直固定在绝缘底座上的两根长直光滑金属导轨间距为L导轨间加有垂直导轨平面向里的匀强磁场B.绝缘火箭支撑在导轨间总质量为m燃料室中的金属棒EF电阻为R通过电刷与导轨保持良好接触.引燃装置下方的推进剂迅速推动刚性金属棒CD电阻可忽略且和导轨接触良好沿导轨向上运动在棒EF中激励出强电流产生电磁推力加速火箭经过时间△t回路CDFE面积减少△S火箭刚好脱离导轨.当火箭脱离导轨时电阻R产生的焦耳热使燃料燃烧形成高温__气体燃烧室下方的可控喷气孔打开喷出燃气进一步加速火箭.不计空气阻力不计导轨的电阻 1求△t时间内棒EF中感应电流的平均值I及火箭脱离导轨时的速度V0 2若火箭总质量m=10kg脱离导轨时的速度V0=20m/s喷气孔在极短的时间内向下喷出质量m′=2kg的燃气燃气相对喷气后火箭的速度为u=100m/s.求喷气后火箭的速度Vl及喷气过程燃料释放的内能Q 3在第2问中若喷气孔将m′=2kg的燃气分两次喷出每次喷出燃气的质量为m′/2燃气相对喷气后火箭的速度均为u=100m/s求喷气后火箭的速度V2.
AboutsixyearsagoItookajobsomepeoplewouldconsideradreamjob.Atthetimeitwasconsideredasecurejobwithgreatbenefits.AstheyearspassedIrealizedIwasjustrepeatingeveryday.SoIdecidedtobeginbuildingmyownbusiness. Iknowwhatyouarethinking﹣there'snosecurityinthat!YeahIknow.IhaveheardthatandaboutonethousandotherreasonswhyIshouldhavecontinuedworkingattheregularjob.ButIdon'tregretmydecision.Iknowmanypeopleouttherealsowanttostarttheirownbusiness.Herearesomethingsyouneedtoknowbeforebreakingthemouldandleavingyour9﹣5toconcentratefull﹣timeonyourdreamThere'sneveraperfecttime.Somethingwillalwayscomeuptopreventyoudefer推迟yourdecisionchangeyourminddiscourageyouorsetyoubackabouttenyears. Havinganexperiencedandtrustedadviserisimportant.Why?Becauseifyoufindonewithasimilarthoughtprocessitislikelythattheyhavewalkedinthepathyouaretaking.Payattentiontotheiradviceasitcansaveyourheartache. Havingallthedetailsfiguredoutisimpossible.Therearesomanythingsyouhavetodobeforelaunchingoutintothedeep.Eitherwaytherearerisksinvolved.Youcanhaveallofyourinsecuritiessolvedandguesswhat!Somethingwillcomeuptomakeamessofeverything.Keepmovingon.Pressthroughit. Theclosertheyarethedeepertheystab.Notallofyourfriendswillcelebrateyourchange.Therewillbethosewhowouldratherdiscourageyouandtellyouhowyouwillnevermakeitbutalltheywouldhavetodoissupportyou.It'syourdream.It'syourresponsibility.Ifyouallowthewordsofotherstokeepyoufromityouweren'tsuitableforit. 25.Whydidtheauthordecidetostarthisownbusiness? A.Hegotfedupwiththeregularjob. B.Hewasencouragedbypeoplearoundhim. C.Hethoughthispreviousjobwasoutofdate. D.Hedidn'tmakegoodmoneyfromtheregularjob. 26.Whatdoestheauthormeanbybreakingthemouldinthesecondparagraph? A.Notobeyingtherulesatwork. B.Learningnewwaystodothejob. C.Gettingoutoftheoldworkplace. D.Improvingtheworkingenvironment. 27.Whichstatementwilltheauthoragreewith? A.Preparationisn'tthatimportantinstartingabusiness. B.Oneshouldjustdoitifhewantstostartabusiness. C.Moredetailsshouldbeconsideredtoreducerisks. D.Oneshouldtakeothers'wordsseriously. 28.What'stheauthor'spurposeinwritingthetext? A.Toexplainwhyhestartedhisownbusiness. B.Tomakehisbusinessknowntomorepeople. C.Togiveadvicetothosewantingtoworkforthemselves. D.Tocomparehavingaregularjobwithstartingabusiness.
假设你是李华最近有关人类带着地球逃离即将毁灭的太阳系去寻找新家园的科幻片流浪地球热映你写了封e﹣mail邀请你的美国朋友John下周六晚上7点半在环球影院GlobalCinema见面一起观看晚上8点的电影. 内容包括 1.电影的简介和你的看法 2.观影的时间和地点 3.… 注意 1.词数100左右 2.可以适当增加细节以使行文连贯. 参考词汇1.session场次 DearJohn How'severything?﹣﹣﹣﹣ Bestwishes. Yours LiHua
Whenwereadapoem.weoftenimaginewhatthepoets1thinkwhentheywroteorwhattheyweredoingatthetime.Thesethoughtsletusconnectwiththewordsbetterasifwe'dcreatedthepoem2we.Willapoemstillmeanasmuchifacomputewritesit? By3useagorithms算法computerscannowcreateallkindsoftextincludingresearchpapersbooksnewsstoriesandevenpoems.Computer﹣generatedpoemsmightbecorrectinbothgrammarandstyle4somesaytheystilllack5createandtruemeaning. AustralianresearcherOscarSchwartzcreatedawebsite6callbotornot.Onhissiteyoucanreadpoemsandguesswhetherthey7writebyahumanoracomputer.SchwartzrecentlygaveaspeechatTedXSydneyin8hestatedthatsomeofthewebsite'spoemswereableto9foolish65percentofhumanreaders. Hesaidthatonhiswebsitehehopedpeoplewouldquestionthedifferencebetweenhumansand machines一andbeabletoidentifywhatitis10makesushuman.
Capsaicin辣椒素canbeusedasmedicinetohelpreducepain.Itmayseemstrangethatwhatcausespainmightalsomakepaingoaway.Yetit'strue. TiborRohacsisamedicalresearcheratNewJerseyMedicalSchoolinNewark.Herecentlystudiedhowcapsaicinworkstoreducepain.ResearchersalreadyknewthatwhencapsaicinturnsontheTRPV1proteinit'sliketurningonabrightlight.Wheneverthelightisonthepersonexperiencespain.Rohacsandhiscolleaguesthendiscoveredachemicalchainreactionthatlatersilencesthispain.HesaysThelightshinessobrightlythatafterawhilethebulbburnsout.ThentheTRPV1proteincan'tturnbackonagain.Whenthishappensthebrainnolongerfindsoutaboutthefeelingofpain. Thehumanbodyisgoodatrepairingitselfhowever.Eventuallythepainwillfixthispainsystemandcanonceagainsendpainalerts警报tothebrain.HoweveriftheTRPV1proteinisactivated激活oftenthepainsystemmaynotgetachancetorepairitselfintime.Thepersonwillonlyfeeldiscomfortorburningatfirst.Thenheorshewillexperiencerelieffromothertypesofpain.Forexamplepeoplewitharthritisregularlyhavepainintheirfingerskneeshipsorotherjoints.Rubbingacreamcontainingcapsaicinontothepainfulareamayburnatfirst.Afterawhilehowevertheareawillbecomenumb. Rohacswarnsthatcapsaicincreamsdon'tseemtogetdeeplyenoughintotheskintototallyremovepain.Hesaysotherresearchersarecurrentlytestingcapsaicinbandagesorinjections.Theywouldlikelydoabetterjobathaltingpain.Unfortunatelytheytendtohurtalotmorethanacream﹣atleastinthebeginning.Someonewhocantoughoutthediscomforthowevercouldfeelnopaininthefollowingseveralweeksnothours. 32.WhathappenstothepersonwhentheTRPV1proteinisturnedon? A.Heloseshissenses. B.Hesuffersphysicalpains. C.Heslightlysensesdiscomfort. D.Hegetsusedtothefeelingofpain. 33.Whenmaythepainsystemnotrecover? A.WhentheTRPV1proteinburnsout. B.Whenthebraincannotreceivepainalerts. C.WhentheTRPV1proteinisturnedonfrequently. D.Whendifferenttypesofpainoccuratthesametime. 34.Whatistheproblemofcapsaicincreamswhentheyareusedtoreducepain? A.Theyarenotveryeffective. B.Theycauseburnsintheskin. C.Theycausetoomuchdiscomfort. D.Theycanstoppainforjustseveralweeks. 35.Whatdoestheunderlinedwordhaltinginthelastparagraphmean? A.Finding.B.Feeling.C.Hiding.D.Stopping.
Ifyouwishtobecomeabetterreaderherearefourimportantthingstorememberaboutreadingrate ●Knowingwhyyouarereadingorwhatyouarereadingtofindoutwilloftenhelpyoutoknowwhethertoreadrapidlyorslowly. ●Somethingsshouldbereadslowlythroughout.Examplesaredirectionsformakingordoingsomethingarithmeticproblemsscienceandhistorybookswhicharefullofimportantinformation.Youmustreadsuchthingsslowlytoremembereachimportantstepandunderstandeachimportantideas. ●Somethingsshouldbereadrapidlythroughout.Examplesaresimplestoriesmeantforenjoymentnewslettersfromfriendspiecesofnewsfromlocalorhome﹣townpaperstellingwhatishappeningtofriendsandneighbors. ●Insomeofyourreadingyoumustchangeyourspeedfromfasttoslowandslowtofastasyougoalong.Youwillneedtoreadcertainpagesrapidlyandthenslowdownanddomorecarefulreadingwhenyoucometoimportantideaswhichmustberemembered. 1Theunderlinedwordrateinthefirstsentencemeans. A.fast B.slow C.speed D.skill 2Whichshouldbereadslowlyaccordingtothepassage? A.Storiesforenjoyment B.Arithmeticproblems C.Lettersfromfriends D.Newsfromhometownnewspapers 3Howfastshouldweread? A.Thefasterthebetter. B.Themoreslowlythebetter. C.Neithertoofastnortooslow. D.Itdependsonwhatwearereading. 4AccordingtothepassagewhichofthefollowingisNOTtrue? A.Readslowlywhenyouarereadingsomethingimportanttoyou. B.Readfastwhenyouarereadingsomethingunimportanttoyou. C.Readthematerialsthatyouareinterestedinslowly. D.Readthematerialsthatyouareinterestedinfast.
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