document.write( "Question 849981: The area of a rectangular piece of cardboard is 945 square inches. The cardboard is used to make an open box by cutting 3-inch squares from each corner and turning up the sides. If the box is to have a volume of 1755 cubic inches, find the dimensions. \n" ); document.write( "
Algebra.Com's Answer #511874 by josgarithmetic(39617)\"\" \"About 
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\n" ); document.write( "x and y, the dimensions. Uncut cardboard.
\n" ); document.write( "\"xy=945\".\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Cutting off corners 3 by 3 square inches.
\n" ); document.write( "Base is \"%28x-2%2A3%29%28y-2%2A3%29\"
\n" ); document.write( "Height is simply 3.\r
\n" ); document.write( "\n" ); document.write( "VOLUME is \"3%28x-6%29%28y-6%29=1755\".
\n" ); document.write( "This volume equation can be a little bit more simplified initially:
\n" ); document.write( "Volume is \"%28x-6%29%28y-6%29=585\".\r
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\n" ); document.write( "\n" ); document.write( "Let me leave this unfinished. The two equations to use are the system:
\n" ); document.write( "-----------------------
\n" ); document.write( "xy=945
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\n" ); document.write( "(x-6)(y-6)=585
\n" ); document.write( "----------------------
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\n" ); document.write( "\n" ); document.write( "The second equation, the volume one gives
\n" ); document.write( "\"xy-6x-6y%2B36=585\"
\n" ); document.write( "And substituting for \"xy=945\" you get after a simplification,
\n" ); document.write( "\"-6x-6y%2B396=0\"
\n" ); document.write( "\"x%2By-66=0\"
\n" ); document.write( "Again substituting from the area as \"y=945%2Fx\", obtain
\n" ); document.write( "after further steps,
\n" ); document.write( ".
\n" ); document.write( "\"highlight_green%28x%5E2-66x%2B945=0%29\"
\n" ); document.write( "-
\n" ); document.write( "Using the general solution to a quadratic equation gives
\n" ); document.write( "\"x=%2866%2Bsqrt%28576%29%29%2F2\"
\n" ); document.write( "\"highlight%28x=45%29\" (we use the positive square root).
\n" ); document.write( "From this and the area equation again, \"highlight%28y=21%29\".
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