document.write( "Question 1145528: A photograph is enlarged to 20cm by 30cm and framed. The frame is to include a border around the photograph equal in area to the photograph. Find the width of the border. \n" ); document.write( "
Algebra.Com's Answer #766980 by ankor@dixie-net.com(22740)\"\" \"About 
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A photograph is enlarged to 20cm by 30cm and framed.
\n" ); document.write( " The frame is to include a border around the photograph equal in area to the photograph.
\n" ); document.write( " Find the width of the border.
\n" ); document.write( ":
\n" ); document.write( "Find the area of the photo: 20 * 30 = 600 sq/cm, border is also 600 so the
\n" ); document.write( "overall area = 1200 sq/cm
\n" ); document.write( "let x = the width of the border therefore:
\n" ); document.write( " overall dimensions is (2x+20) by (2x+30)
\n" ); document.write( "Area equation
\n" ); document.write( "(2x+20)*(2x+30) = 1200
\n" ); document.write( "FOIL
\n" ); document.write( "4x^2 + 60x + 40x + 600 = 1200
\n" ); document.write( "4x^2 + 100x + 600 - 1200 = 0
\n" ); document.write( "4x^2 + 100x - 600 = 0
\n" ); document.write( "simplify, divide by 4
\n" ); document.write( "x^2 + 25x - 150 = 0
\n" ); document.write( "You can use the quadratic formula, a=1; b=25; c=-150; but this will factor to:
\n" ); document.write( "(x+25)(x-5) = 0
\n" ); document.write( "Positive solution
\n" ); document.write( "x = 5 cm is the width of the border
\n" ); document.write( ":
\n" ); document.write( ":
\n" ); document.write( "Check this out
\n" ); document.write( "(2(5)+20) * (2(5) + 30) =
\n" ); document.write( "30 * 40 = 1200 \n" ); document.write( "
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