document.write( "Question 1156439: The Mona Lisa is a famous painting by Leonardo da Vinci. The painting is 30 inches by 21 inches. It is surrounded by a frame of uniform thickness whose area (not including the center) is 756 inches squared. Find the thickness of the frame. \n" ); document.write( "
Algebra.Com's Answer #779127 by josgarithmetic(39616)\"\" \"About 
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the uniform \"thickness\", u\r
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\n" ); document.write( "\n" ); document.write( "\"%2830%2B2u%29%2821%2B2u%29-30%2A21=756\"
\n" ); document.write( "Simplify, and continue from this.
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