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Mathematics>Standard Multiple Choice

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

An art gallery displays a large painting in the center of a wall that is 24 feet (ft) wide. The painting is 10   text ft end text wide. Which of the following equations can be used to find the distance, x, in feet, from either end of the wall to the corresponding edge of the painting?

A.|x-10|=12
B.2|x-12|=10
C.2|x-10|=12
D.|x-12|=10

答案和解析

答案：B

解析：

Choice B is correct. The center of the wall is a distance of 1/2(24)=12 feet from the left end of the wall. If x is the distance from a painting edge to its corresponding end of the wall, then |x-12| is the distance from the painting edge to the center of the wall.

If the painting is centered, then 2|x-12| represents the width of the painting.

Since the painting is 10ft wide, we have 2|x-12|=10.