代数Algebra与几何Geometry双语表达40句1.Anumericalexpression数值表达式containsonlynumbers:3+62.Avariableexpression变量表达式containsnumbersandvariables:3+b3.Anexpression表达式isanumberphrasewithoutanequalsign等号.Avariableisasymbol,usuallyaletter,thatstandsforanunknownnumberorquantity.4.Analgebraicexpression代数式isanumber,variable,orcombinationofnumberandvariables,connectedbyamathematicaloperationlikeaddition,subtraction,multiplication,ordivision.Forexample,intheexpressionx+5,xisthevariable.5.TheCommutative交换PropertiesofAddition加法andMultiplication乘法statethattheorderinwhichnumbersareaddedormultiplieddoesnotchangetheresult.Forexample:a+b=b+a,2+3=5,3+2=5,5×2=10,2×5=106.TheAssociatePropertiesofAdditionandMultiplicationstatethatthewayinwhichaddendsandfactorsaregroupeddoesnotchangetheresult.Forexample:(a+b)+c=a+(b+c),(2+3)+4=2+(3+4)7.ThePropertiesofZerostatethatttheproductofafactorand0is0.Theyalsostatethatthequotientofzeroandanynon-zerodivisoris0.Forexample:a×0=0,0÷5=08.Anequationisamathematicalsentencethatstatesthattwoexpressionsarenotequal.Itcontainsanequalssign.2+5=7,2+c=79.Aninequationisamathematicalsentencethatstatesthattwoexpressionsareequal.Itshowstwonumbersorexpressionscomparetooneanother.2+5>6,2+5<910.Ifanexpressioncontainstwoormoreoperations,theymustbecompletedinaspecifiedorder.Theorderofoperationsisasfollows:Doalloperationswithinparentheses圆括号and/orbrackets括弧(innermostfirst).Doallmultiplications乘法anddivisions除法,inorderfromlefttoright.Doalladditions加法andsubtractions减法,inorderfromlefttoright.3×(4+5)+6÷3Dotheoperationswithintheparethesesfirst.3×9+6÷3Multifyanddividefromlefttoright.11.Acoordinateplane坐标平面isformedbytwointersectingnumberlines.Thehorizontallineiscalledthex-axis.Theverticallineiscalledy-axis.Thetwo-axissystemiscalledthecoordinatesystem座标系.112.Thecoordinatesofapointarepresentedbytheorderedpair(x,y).Thisshowsthedistancethepointisfromtheorigin(0,0),inthedomain(thesetofxcoordinates)andtherange(thesetofycoordinates).13.Integers整数arethesetofwholenumbersandtheiropposites.Positiveintegers正整数aregreaterthanzero.Negativeintegers负整数arelessthanzero.Anegativeintegerislessthanapositveinteger.Thesmalleroftwointegersisalwaysthezerototheleftonthnumberoftheline.14.Theoppositeof4is-4.Theyareboth4spacesfrom0.15.Thesumoftwopositiveintegersispositive.(negative?)4+3=7,-4+(-3)=-716.TheAdditionandSubtractionPropertiesofEqualitystatethatwhenthesamenumberisaddedtobothsidesofanequation,thetwosidesremainequal:4+17+5=21+517.TheMultiplicationandDivisionPropertiesofEqualitystatethatwheneachsideoftheequationismultipliedbythesamenumber,thetwosidesremainequal.(3+4)×5=7×518.Afraction分数issimplified,orreducedtolowestterms,whenitsnumberator分子anddenominator分母havenocommonfactors公约数otherthan1.Tosimplifyafraction,dividethenumberatoranddenominatorbytheirgreatestcommonfactor.19.Useexponents指数toshowhownumberswiththesamebasearemultipliedanddivided:20.Ifatownwithpopulationof3,000growsby2%peryear,howlargewillthpopulationbein10years?(Hint:tofindthepopulationafter1year,multiplyby1.02)--Thetown’spopulationwillbe__________after10years.21.Parallellines平行线donotcrossorintersect交叉andareequidistant距离相等的fromeachother.22.2:1-Atwotooneratio;twotoone;23.Thesumoftheanglesinarectangle长方形addupto360degrees.24.Apoint,inthemathematicalsense,isalocationinspacethatdoesnothavesizeorshape.25.Alineissetofconnectedpointswithoutendpoints终点.226.Alinesegment部分,inthemathematicalsense,isasetofconnectedpointswithtwoendpoints.27.Aray,inthemathematicalsense,isalinethathasoneendpointandcontinuesindefinitelyinonedirection.28.Anangleisageometric几何学的figureformedbytworaysthatconnectatasinglepointorvertex角的顶点.29.Thevertexisthepointofintersectionofthelinesorraysthatformanangle.30.Therulermeasured8centimeters(cm).31.Anacuteangle锐角isananglethatislessthan90degrees.32.Arightangle直角isananglethatisexactly90degrees.33.Anobtuseangle钝角isananglethatisgreaterthan90degreesbutlessthan180degrees.34.Thesumofthethreeanglesofatriangleisequalto180degrees.35.Aquadrilateral四边形isaclosedfigurewithfoursidesandfourvertices.36.Aparallelogram平行四边形isaquadrilateralwithoppositesideswhichareparallelandcongruent.37.Atrapezoid梯形/不等边四边形isaquadrilateralwithonepairofoppositesidesthatareparallel.(Anoctagon八边形haseightsides.)38.Congruent全等的meansexactlythesameorequal.39.Ingeometry,similarcanmeanthattwofigureshavethesameshapebutnotthesamesize.40.Thecircumference圆周isthemeasureofthedistancearoundtheoutsideedgeofacircle.3
