首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
On the number line shown above, the tick marks are equally spaced. Which of the following statements about the numbers x, y, and
On the number line shown above, the tick marks are equally spaced. Which of the following statements about the numbers x, y, and
admin
2014-08-12
36
问题
On the number line shown above, the tick marks are equally spaced. Which of the following statements about the numbers x, y, and z must be true?
Indicate
all
such statements.
选项
A、xyz<0
B、x + z =y
C、z(y-x)>0
答案
A,B,C
解析
You can see from their positions on the number line that x is less than 0 and both y and z are greater than 0. Because the tick marks are equally spaced, you can also see that x = -y and z = 2y. You need to evaluate each answer choice separately to determine whether it must be true.
Choice A says that the product of the three numbers x, y, and z is less than 0. Recall that the product of three numbers is negative under either of the following two conditions.
All three numbers are negative.
One of the numbers is negative and the other two numbers are positive.
Choice A must be true, since x is negative and y and z are positive.
Choice B is the equation x + z = y. To see whether the equation must be true, it is a good idea to express two of the variables in terms of the third(that is, to "get rid of" two of the variables). The equations x = — y and z = 2y give x and z in terms of y, so the equation x + z =y can be rewritten, substituting —y for x and 2y for z, as —y + 2y =y. In this form you can quickly conclude that the equation must be true.
Choice C says that the product of the two numbers z and y - x is greater than 0. Recall that the product of two numbers is positive under either of the following two conditions.
Both numbers are positive.
Both numbers are negative.
Since you already know that z is positive, you can conclude that the product z(y - x)will be positive if y - x is positive. By adding x to both sides of the inequality y - x > 0, you can see that it is equivalent to the inequality y > x, which is clearly true from the number line. Since y — x is positive, the product z(y - x)must be positive.
Therefore, the correct answer consists of Choices A, B, and C.
转载请注明原文地址:https://kaotiyun.com/show/kykO777K
本试题收录于:
GRE QUANTITATIVE题库GRE分类
0
GRE QUANTITATIVE
GRE
相关试题推荐
Itisanunfortunatefactoftoday’slifethatmostpeoplearegrowingupunabletoseethestars.Theprimenightskyexistson
Somepeoplethinkoflifeasagame.Therearesimilaritiesbetweenlifeandgames;bothcanbeplayed,bothhaverules,andbot
AsTheplanecircledovertheairport,everyonesensedthatsomethingwaswrong.Theplanewasmovingunsteadilythroughtheair
Peopleallovertheworldtodayarebeginningtohearandlearnmoreandmoreabouttheproblemofpollution.Pollutioniscause
Thousandsofyearsago,inthemiddleofanocean,milesfromthenearestisland,anunderseavolcanobrokeout.Thehotliquid
Long-distancerunnersmayattimesworryabouttheirhearthealthwhiletakingpartintheevents.Butastudyfindsthatheats
TheCalifornialawmakersvotedThursdaytoraisethelegalagetobuytobaccoproductsfrom18to21.Themeasureispartofal
______thattheymayeventuallyreducetheamountoflaborneededonconstructionsitesby90percent.
Withtheconstantchangeofconditions,theoutcomeisnotalways______.
Evaluatethefollowing.(a)15-(6-4)(-2)(b)(2-17)÷5(c)(60÷12)-(-7+4)(d)(3)4-(-2)3(e)(-5)(-3)-15(f)(-2)4(15-18)4(g)(20÷5)2
随机试题
“史家之绝唱,无韵之《离骚》”这句话是对我国历史上哪一部著作的赞誉?()
影响能量代谢最重要的因素是()
盆腔区照片避孕环的正常位置是
某咨询企业接受了2个业务的咨询,一个是能填补市场空白的特种钢板加工项目,一个是科技领先性项目。其中,工业加工项目是属于核准范围的项目,该企业还准备接受该项目的后评价的咨询任务。在前期咨询时,市场需求预测拟分别采用回归模型作短期预测,弹性系数法作近期预
下列选项所述情况下,业主方与施工方的施工合同有效的一项是()。
箱涵顶进在穿越铁路路基时,在()情况下,可采用低高度施工便梁方法。
两条平行暗挖隧道相距小于1倍洞跨时,其开挖面前后错开距离不得小于()。
沟通联络的主要作用有()。
下列叙述中正确的是()。
Ninety-fivepercentofadultAmericanssleepseventoeighthoursanight.Therestseemtoneedmorethanninehours,orgetal
最新回复
(
0
)