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2013年10月22日SAT官方每日一题---数学选择

  下面是2013年10月22日的SAT官方每日一题的内容,是关于数学方面的,题型是选择。SAT官方每日一题是collegeboard每天都会发布的题目,关于SAT考试的三个部分的各个题型。大家和无忧小编一起来看一下这个SAT官方每日一题吧。

  SAT官方每日一题之数学---选择:

  Mathematics > Standard Multiple Choice

  Read the following SAT test question and then click on a button to select your answer.

  If(x + y)^2 = (x^2) + (y^2), which of the following statements must also be true?

  Roman numeral 1.x = 0

  Roman numeral 2.(x minus y)^2 = (x^2) + (y^2)

  Roman numeral 3.x times y = 0

  (A) None

  (B)Roman numeral 1only

  (C)Roman numeral 2only

  (D)Roman numeral 3only

  (E)Roman numeral 2andRoman numeral 3

  The correct answer is E

  Explanation

  The quantity(x + y)^2can be expressed as(x^2) + (2 times x times y) + (y^2). If(x + y)^2 = (x^2) + (y^2), then2 times x times y = 0andx times y = 0. Sincex times y = 0, eitherx = 0ory = 0or both. Therefore, statementRoman numeral 3must be true, but statementRoman numeral 1,x = 0, is not always true. For statementRoman numeral 2, you can write(x minus y)^2 = (x^2) minus (2 times x times y) + y^2, and sincex times y = 0, it follows that(x minus y)^2 = (x^2) + (y^2). Therefore, both statementsRoman numeral 2andRoman numeral 3must be true.

  下面为大家提供一些和这些SAT官方每日一题相似的题目,供大家练习:

  Ifx + (2 times x)is5more thany + (2 times y), thenx minus y = 

  (A)negative 5 

  (B)negative (5 over 3) 

  (C)3 over 5 

  (D)5 over 3 

  (E)5 

  The correct answer is D

  Explanation

  The statement given in words translates into the equationx + (2 times y) = y + (2 times y) + 5. This simplifies to3 times x = (3 times y) + 5. Then(3 times x ) minus (3 times y) = 5, and so3 times (x minus y) = 5.

  It follows thatx minus y = (5 over 3).

  以上就是关于2013年10月22日SAT官方每日一题中数学部分的详细内容,包括了题目和选项以及答案,后面附有一道相关的练习题。大家可以在备考SAT的过程中关注SAT每日一题的内容,这样就可以更好有不间断的练习,也就能在日积月累的过程中得到提高。