document.write( "Question 853664: Marie Mulroney has a rectangular board 12 inches by 16 inches around which she wants to put a uniform border of shells. If she had enough shells for a border whose area is 128 square inches, determine the width of the border. \n" ); document.write( "
Algebra.Com's Answer #514254 by ankor@dixie-net.com(22740)\"\" \"About 
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Marie Mulroney has a rectangular board 12 inches by 16 inches around which she wants to put a uniform border of shells.
\n" ); document.write( " If she had enough shells for a border whose area is 128 square inches, determine the width of the border.
\n" ); document.write( ":
\n" ); document.write( "Find the area of the of the board: 12 * 16 = 192 sq inches
\n" ); document.write( "then
\n" ); document.write( "128 + 192 = 320 sq/in, area of the board and the border
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\n" ); document.write( "Let x = the width of the border
\n" ); document.write( ":
\n" ); document.write( "(x+12)(x+16) = 320
\n" ); document.write( "FOIL
\n" ); document.write( "x^2 + 16x + 12x + 192 - 320 = 0
\n" ); document.write( "x^2 + 28x - 128 = 0
\n" ); document.write( "Factors to
\n" ); document.write( "(x+32)(x-4) = 0
\n" ); document.write( "The positive solution is all we want here
\n" ); document.write( "x = 4 inches is the border width.
\n" ); document.write( ":
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\n" ); document.write( "Check this, find the find the total area with 4\" added
\n" ); document.write( "16 * 20 = 320 sq/in
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