document.write( "Question 198086: The bottom and top of a box are rectangles twice as long as they are wide. Find the volume of the box if it is 4 ft high and has a total surface area of 220 ft². \n" ); document.write( "
Algebra.Com's Answer #148609 by ankor@dixie-net.com(22740)\"\" \"About 
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The bottom and top of a box are rectangles twice as long as they are wide.
\n" ); document.write( " Find the volume of the box if it is 4 ft high and has a total surface area of 220 ft²
\n" ); document.write( ":
\n" ); document.write( "Let x = the width
\n" ); document.write( "then
\n" ); document.write( "2x = the length
\n" ); document.write( ":
\n" ); document.write( "The box dimensions: 2x by x by 4
\n" ); document.write( "Given the surface area:
\n" ); document.write( "2(2x*x) + 2(2x*4) + 2(x*4) = 220
\n" ); document.write( ":
\n" ); document.write( "4x^2 + 16x + 8x = 220
\n" ); document.write( "A quadratic equation:
\n" ); document.write( "4x^2 + 24x - 220 = 0
\n" ); document.write( "simplify, divide by 4
\n" ); document.write( "x^2 + 6x - 55 = 0
\n" ); document.write( "Factor
\n" ); document.write( "(x+11)(x-5) = 0
\n" ); document.write( "The positive solution is what we want here:
\n" ); document.write( "x = 5 ft is the width
\n" ); document.write( "then
\n" ); document.write( "2(5) = 10 ft is the length
\n" ); document.write( ":
\n" ); document.write( "Find the volume
\n" ); document.write( "10 * 5 * 4 = 200 cu/ft is the volume \n" ); document.write( "
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