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大华雅思
大华雅思
SAT1官网每日一题之数学篇(十)
sat考试官方网站每日一题小结,以下是SAT1数学部分。
Read the following SAT test question, then click on a button to select your answer.
 
   In the figure, the slope of the line through points P and Q is
. What is the value of k?
   A.4
   B.5
   C.6
   D.7
   E.8
  
Correct Answer: B
  
Here's Why:
   The slope of a line in a coordinate plane is given by the fraction whose numerator is the change in y between any two points on the line and whose denominator is the change in x between the same points on the line.
   The question asks for the value of k, which is the x-coordinate of point Q.
   The change in y between points P and Q is 7 – 1 = 6. The change in x between these points is k – 1. Since the slope is
, it follows that   = . Solving this equation gives 3k – 3 = 12. Therefore, 3k = 15, and k = 5.
   Difficulty: Medium
   Question Type: Standard Multiple Choice
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