document.write( "Question 68566: The legs in a right triangle equal 3x and 20. The hypotenuse of the triangle is 4x-1. Find the value of x. \n" ); document.write( "
Algebra.Com's Answer #48805 by Edwin McCravy(20055)\"\" \"About 
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The legs in a right triangle equal 3x and 20. \r\n" );
document.write( "The hypotenuse of the triangle is 4x - 1. \r\n" );
document.write( "Find the value of x.\r\n" );
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document.write( "            a = 3x\r\n" );
document.write( "            b = 20\r\n" );
document.write( "            c = 4x - 1\r\n" );
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document.write( "      a² + b² = c²\r\n" );
document.write( "(3x)² + (20)² = (4x - 1)²\r\n" );
document.write( "    9x² + 400 = (4x - 1)(4x - 1)\r\n" );
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document.write( "Use FOIL on the right side\r\n" );
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document.write( "    9x² + 400 = 16x² - 4x - 4x + 1\r\n" );
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document.write( "    9x² + 400 = 16x² - 8x + 1\r\n" );
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document.write( "            0 = 16x² - 8x + 1 - 9x² - 400\r\n" );
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document.write( "            0 = 7x² - 8x - 399\r\n" );
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document.write( "That will factor as\r\n" );
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document.write( "            0 = (x + 7)(7x - 57)\r\n" );
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document.write( "         x + 7 = 0 gives x = -7\r\n" );
document.write( "       7x - 57 = 0 gives x = 57/7\r\n" );
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document.write( "Since a triangle cannot have negative\r\n" );
document.write( "sides, we discard x = -7.  So the answer\r\n" );
document.write( "is x = 57/7 \r\n" );
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document.write( "Edwin
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