document.write( "Question 162783This question is from textbook Elementary and Intermediate \n" );
document.write( ": Avoiding a collision. A car is traveling on a road that is perpendicular to a railrod track. When the car is 30 meters from the crossing, the car's new collision detector warns the driver that there is a train 50 meters from the car and heading toward the same crossing. How far is the train from the crossing?\r \n" );
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document.write( "It would really help if you draw out the problem to visualize what is happening...when you do you realize that you create a right triangle where one leg is 30 meters and the hypotenous is 50 meters and they are asking for the other leg...a Pythagorean Theorem problem\r \n" );
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document.write( "a^2 + b^2 = c^2 \n" );
document.write( "(30)^2 + b^2 = (50)^2 \n" );
document.write( "900+ b^2 = 2500 \n" );
document.write( "900-900 +b^2 = 2500-900 \n" );
document.write( "0 + b^2 = 1600 \n" );
document.write( "sqr (b^2) = sqr (1600) \n" );
document.write( "b = 40 or b=-40\r \n" );
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document.write( "but since in this case we are talking about distance which is always a positive number, then our answer is 40 meters \n" );
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