document.write( "Question 809358: word problem is: the total surface area of a closed box is 350 square meters. the boxes 9 meters high and has a square base and lid. find the length of a side of the base? \n" ); document.write( "
Algebra.Com's Answer #487708 by ankor@dixie-net.com(22740)\"\" \"About 
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the total surface area of a closed box is 350 square meters.
\n" ); document.write( " the boxes 9 meters high and has a square base and lid.
\n" ); document.write( " find the length of a side of the base?
\n" ); document.write( ":
\n" ); document.write( "let x = one side of the square base
\n" ); document.write( "then
\n" ); document.write( "2x^2 = the area of the top and bottom of the box
\n" ); document.write( "and
\n" ); document.write( "4(9x) = the area of the 4 sides
\n" ); document.write( ":
\n" ); document.write( "Surface area equation
\n" ); document.write( "2x^2 + 4(9x) = 350
\n" ); document.write( "simplify, divide by 2
\n" ); document.write( "x^2 + 2(9x) = 175
\n" ); document.write( "A quadratic equation
\n" ); document.write( "x^2 + 18x - 175 = 0
\n" ); document.write( "Factors to
\n" ); document.write( "(x+25)(x-7) = 0
\n" ); document.write( "The positive solution
\n" ); document.write( "x = 7 meters, the side of the square base
\n" ); document.write( ":
\n" ); document.write( ";
\n" ); document.write( "Check
\n" ); document.write( "2(7^2) + 4(7*9) = 350 \n" ); document.write( "
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