国际学校初中数学英文练习与答案-(2)

初中数学英文练习Objective-Tosolvesimpleequationsinvolvingadditionandsubtraction.50580802323IdentityPropertyofAdditionx0xadditiveidentityEquation-Amathematicalsentencethatshowstwoexpressionsareequal.=8+412“fulcrum”Equationsmustalwaysstayperfectlybalanced.Determinewhichvalueisthecorrectsolutiontotheequation.1)8x13x3,5,7,or8x52)m920m10,4,8,or11m113)12p5p3,4,7,or8p74)t1411t7,3,3,or11t3AdditionPropertyofEqualityIfa=b,thena+c=b+corGivena=bandc=cthena+c=b+cSubtractionPropertyofEqualityIfa=b,thena-c=b-corGivena=bandc=cthena-c=b-c=x+37-3Heavier=x7Heavier=x7Heavier=x7Heavier=x7Heavier=x+37-3-3=x4Algebraically,x+3=7-3-3x=4x+3=7x=4x+3-3=7-31)Goal:Isolatethevariableononesideoftheequation.2)Alwaysperformthesameoperationtobothsidesofanequation.3)Toundoanoperation,performitsoppositeoperationtobothsidesoftheequation.Solvetheequationsbelow.1)x+3=10-3-3x=72)y-8=11+8+8y=193)n+5=11-5-5n=64)13=x+5-5-58=x5)12=n-3+3+315=n6)11+3=k14=kTranslatethesentenceintoanequationandsolve.1)Thesumofkand13is28.2)Fiveisthedifferenceoftand4.k+13=28-13-13k=155=t-4+4+49=tFive-StepPlan1)Readtheproblem.•Drawapicture.•Makeachart.2)Determinetheunknowns.•Defineanunknownwithavariable.•Defineallotherunknownsintermsoffirstvariable.3)Writeanequationinvolvingthevariable.4)Solvetheequation.5)Checkyouranswer.1)Mattscoreda85onhislasttest.Thisis16pointshigherthanhescoredonhisfirsttest.Whatwashisscoreonthefirsttest?Lett=firsttestscore8516t161669tfirsttestscore69Defineavariable,writeanalgebraicequation,andsolve.2)Agazellecanrunataspeedof50mph.Thisis10mphslowerthanthespeedofacheetah.Whatisthespeedofacheetah?Letx=thespeedofacheetah50=-10x+10+1060=xcheetahspeed=60Defineavariable,writeanalgebraicequation,andsolve.3)TheSearsToweris110storiestall.Thisis8storiestallerthantheEmpireStateBuilding.HowmanyfloorsistheEmpireStateBuilding?Letx=the#ofstoriesinEmpireState110=+8x-8-8102=x#FloorsinEmpireState=102Defineavariable,writeanalgebraicequation,andsolve.4)Asubmarineis50metersbelowthesurfaceoftheocean.Ascubadiveris5metersbelowthesurface.Writeanequationtofindtheirdifferenceinelevationandsolve.Letx=differenceinelevation-50+x=-5+50+50x=45Differenceinelevation=45