document.write( "Question 618657: the ratio of two sides of a parallelogram is 3:5 and its perimeter is 48cm. find the sides of the parallelogram. \n" ); document.write( "
Algebra.Com's Answer #389070 by math-vortex(648)\"\" \"About 
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Hi, there--
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\n" ); document.write( "Recall that a parallelogram has two pairs of parallel sides. We will use two variables to solve this problem.
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\n" ); document.write( "Let x be the length of each of the shorter pair of parallel sides.
\n" ); document.write( "Let y be the length of each of the longer pair of parallel sides.
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\n" ); document.write( "We will use the information given in the problem to write two equations that model the problem. The perimeter (48 cm.) is the sum of the four sides, so
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\n" ); document.write( "\"48=x%2Bx%2By%2By\"
\n" ); document.write( "\"2x%2B2y=48\"
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\n" ); document.write( "The ratio of two sides of the parallelogram is 3:5. Since the parallel sides of a parallelogram have equal length, we know that we are comparing the lengths x and y here, so
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\n" ); document.write( "\"x%2Fy=3%2F5\"
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\n" ); document.write( "NOTE: We set up the variables so that x is shorter than y. So \"x is to y as 3 is to 5.\"
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\n" ); document.write( "Now we have two variables and two equations. We can solve the system to find the values of x and y.
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\n" ); document.write( "Rewrite the first equation in terms of x.
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\n" ); document.write( "\"2x%2B2y=48\"
\n" ); document.write( "\"2y=48-2x\"
\n" ); document.write( "\"y=24-x\"
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\n" ); document.write( "Substitute 24-x for y in the second equation.
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\n" ); document.write( "\"x%2Fy=3%2F5\"
\n" ); document.write( "\"x%2F%2824-x%29=3%2F5\"
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\n" ); document.write( "Solve for x. I will skip a bunch of algebra steps and cross-multiply.
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\n" ); document.write( "\"5x=3%2824-x%29\"
\n" ); document.write( "\"5x=72-3x\"
\n" ); document.write( "\"8x=72\"
\n" ); document.write( "\"x=9\"
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\n" ); document.write( "We now know that the shorter sides have a length of 9 cm. Substitute 9 for x in the first equation.
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\n" ); document.write( "\"2x%2B2y=48\"
\n" ); document.write( "\"2%289%29%2B2y=48\"
\n" ); document.write( "\"18%2B2y=48\"
\n" ); document.write( "\"2y=48-18=30\"
\n" ); document.write( "\"y=15\"
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\n" ); document.write( "According to this equation, the length of the longer side is 15 cm.
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\n" ); document.write( "Now we side to check our work. The perimeter is 48 cm.
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\n" ); document.write( "\"9%2B9%2B15%2B15=48\"
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\n" ); document.write( "The perimeter checks out. Now we need to check that the ratio of the two sides reduces to 3:5. The ratio 9:15 is equivalent to 3:5 because we can divide both parts by their common factor,3. That is, 9/3=3 sand 15/3=5.
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\n" ); document.write( "Check! So the lengths of the sides of the parallelogram are 9 cm and 15 cm.
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\n" ); document.write( "Hope this helps. Feel free to email me if you have questions about this.
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\n" ); document.write( "Ms.Figgy
\n" ); document.write( "math.in.the.vortex@gmail.com
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