2004 AMC 10A Problem 4

Below is the professionally curated solution for Problem 4 of the 2004 AMC 10A, from LIVE by Po-Shen Loh. You can also try the full timed exam, view all 2004 AMC 10A solutions, or check the answer key.

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Concepts:absolute valuemidpoint

Difficulty rating: 1030

4.

What is the value of xx if x1=x2?|x - 1| = |x - 2|?

12-\dfrac{1}{2}

12\dfrac{1}{2}

11

32\dfrac{3}{2}

22

Solution:

Since x1|x - 1| and x2|x - 2| are the distances from xx to 11 and 2,2, the point xx is equidistant from 11 and 2.2.

That midpoint is x=1+22=32. x = \dfrac{1 + 2}{2} = \dfrac{3}{2}.

Thus, the correct answer is D.

Problem 4 in Other Years