document.write( "Question 1110126: The perimeter of a trapezoid is 39a-7. Three sides have the following lengths: 9a, 5a+1, and 17a-6. What is the length of the fourth side. (sorry if the topic/category is incorrect) \n" ); document.write( "
Algebra.Com's Answer #725126 by josgarithmetic(39621)\"\" \"About 
You can put this solution on YOUR website!
Unknown side, x.\r
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\n" ); document.write( "\n" ); document.write( "\"9a%2B%285a%2B1%29%2B%2817a-6%29%2Bx=39a-7\";
\n" ); document.write( "Solve this for x, in terms of a.
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