document.write( "Question 311575: The sum of the lengths of any two sides of a triangle must be greater than the third side. If a triangle has one side that is 18cm and a second side that is 3cm less than twice the third side, what are the possible lengths for the second and third sides? \n" ); document.write( "
Algebra.Com's Answer #222856 by Edwin McCravy(20055)\"\" \"About 
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The sum of the lengths of any two sides of a triangle must be greater than the third side. If a triangle has one side that is 18cm and a second side that is 3cm less than twice the third side, what are the possible lengths for the second and third sides?
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document.write( "The three sides are:  \r\n" );
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document.write( "First side   = 18\r\n" );
document.write( "Third side   = x\r\n" );
document.write( "Second side  = 2x - 3\r\n" );
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document.write( "First side  + Second side > Third Side,   therefore   18 + (2x - 3) > x     \r\n" );
document.write( "First side  + Third side  > Second Side,  therefore          18 + x > 2x - 3\r\n" );
document.write( "Second side + Third side  > Second Side,  therefore    (2x - 3) + x > 18 \r\n" );
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document.write( "So we have:\r\n" );
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document.write( "\"system%2818+%2B+%282x+-+3%29+%3E+x%2C+18+%2B+x+%3E+2x+-+3%2C+%282x+-+3%29+%2B+x+%3E+18%29\"\r\n" );
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document.write( "Simplifying:\r\n" );
document.write( "\"system%2818+%2B+2x+-+3+%3E+x%2C+18+%2B+x+%3E+2x+-+3%2C+2x+-+3+%2B+x+%3E+18%29\"\r\n" );
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document.write( "Simplifying further:\r\n" );
document.write( "\"system%2815+%2B+2x++%3E+x%2C+21+%3E+x+%2C+3x+-+3+%3E+18%29\"\r\n" );
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document.write( "Simplifying further:\r\n" );
document.write( "\"system%28x++%3E-15+%2C+21++%3E+x+%2C+3x+%3E+21%29\"\r\n" );
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document.write( "Simplifying further:\r\n" );
document.write( "\"system%28x++%3E-15+%2C+21++%3E+x+%2C+x+%3E+7%29\"\r\n" );
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document.write( "We can eliminate the first inequality, since the third one guarantees it\r\n" );
document.write( "because if x is greater than 7 it is CERTAILY greater than =15.\r\n" );
document.write( "\"system%28+21++%3E+x+%2C+x+%3E+7%29\"\r\n" );
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document.write( "Those two inequalities can be combined as\r\n" );
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document.write( "\"21+%3E+x+%3E+7\"\r\n" );
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document.write( "or if we prefer:\r\n" );
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document.write( "\"7+%3C+x+%3C+21\", which is the same thing.\r\n" );
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document.write( "So the third side, x, is greater than 7 but less than 21.\r\n" );
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document.write( "Since the Second side is 2x - 3, we must build 2x - 3\r\n" );
document.write( "from the x which is in the middle of \"7+%3C+x+%3C+21\".\r\n" );
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document.write( "To make the x into a 2x, we multiply all three sides of\r\n" );
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document.write( "\"7+%3C+x+%3C+21\" by 2, getting\r\n" );
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document.write( "\"14+%3C+2x+%3C+42\",\r\n" );
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document.write( "To make the 2x into a 2x - 3, we subtract 3 from all three sides of the above:\r\n" );
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document.write( "\"14+-+3+%3C+2x+-+3%3C+42+-+3\"\r\n" );
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document.write( "Simplifying\r\n" );
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document.write( "\"11+%3C+2x-3%3C39\"\r\n" );
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document.write( "So  \"11+%3CSecond_side%3C39\" \r\n" );
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document.write( "So the Second side, 2x - 3, is greater than 11 but less than 39.\r\n" );
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document.write( "Edwin
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