document.write( "Question 837711: The perimeter of an airplane ticket is 30 centimeters. The area is 50 square centimeters. What are the dimensions of the ticket? \n" ); document.write( "
Algebra.Com's Answer #504727 by Theo(13342)\"\" \"About 
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perimeter is equal to 2L + 2W
\n" ); document.write( "area is equal to L * W
\n" ); document.write( "you get 2 equations:
\n" ); document.write( "30 = 2L + 2W
\n" ); document.write( "50 = L*W\r
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\n" ); document.write( "\n" ); document.write( "we'll solve by substitution.
\n" ); document.write( "you can use either equation to solve for either variable.\r
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\n" ); document.write( "\n" ); document.write( "we'll use the second equation to solve for L.\r
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\n" ); document.write( "\n" ); document.write( "second equation is:
\n" ); document.write( "50 = L*W
\n" ); document.write( "divide both sides of this equation by W to get:
\n" ); document.write( "L = 50/W\r
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\n" ); document.write( "\n" ); document.write( "we now have a value of L that we can substitute in the first equation which we can then use to solve for W.\r
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\n" ); document.write( "\n" ); document.write( "the first equation is:
\n" ); document.write( "30 = 2L + 2W
\n" ); document.write( "replace L with 50/W to get:
\n" ); document.write( "30 = 2*(50/W) + 2W
\n" ); document.write( "simplify to get:
\n" ); document.write( "30 = 100/W + 2W
\n" ); document.write( "multiply both sides of this equation by W to get:
\n" ); document.write( "30W = 100 + 2W^2
\n" ); document.write( "subtract 30W from both sides of this equation to get:
\n" ); document.write( "2W^2 - 30W + 100 = 0
\n" ); document.write( "factor this equation to get:
\n" ); document.write( "(2W - 20) * (W - 5) = 0
\n" ); document.write( "solve for W to get:
\n" ); document.write( "W = 10 or W = 5\r
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\n" ); document.write( "\n" ); document.write( "if W = 10, then use the equation of 50 = L*W to get L = 5
\n" ); document.write( "if W = 5, then use the equation of 50 = L*W to get L = 10\r
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\n" ); document.write( "\n" ); document.write( "you have 2 possible solutions.
\n" ); document.write( "L = 5 and W = 10 or:
\n" ); document.write( "L = 10 and W = 5
\n" ); document.write( "both are plausible so we'll test them both out.\r
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\n" ); document.write( "\n" ); document.write( "when L = 5 and W = 10:
\n" ); document.write( "the first equation becomes 2*5 + 2*10 = 10 + 20 = 30
\n" ); document.write( "the second equation becomes 5*10 = 50
\n" ); document.write( "both equations confirm that the solution of L = 5 and W = 10 is good.\r
\n" ); document.write( "\n" ); document.write( "when L = 10 andW = 5:
\n" ); document.write( "the first equation becomes 2*10 + 2*5 = 20 + 10 = 30
\n" ); document.write( "the second equation becomes 10*5 = 5
\n" ); document.write( "both equations confirm that the solution of L = 10 and W = 5 is good.\r
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\n" ); document.write( "\n" ); document.write( "the ticket can have either:\r
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\n" ); document.write( "\n" ); document.write( "a length of 5 and a width of 10 or:
\n" ); document.write( "a length of 10 and a width of 5.\r
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\n" ); document.write( "\n" ); document.write( "since the length is usually longer than the width, you are free to choose that the ticket most likely has a length of 10 and a width of 5.\r
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\n" ); document.write( "\n" ); document.write( "alternatively, you can simply say that the dimensions are 5 by 10 and let the recipient of that information determine which is the length and which is the width.\r
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\n" ); document.write( "\n" ); document.write( "mathematically, the length can be 10 and the width 5 or the length can be 5 and the width 10. \r
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