document.write( "Question 117597: a rectangular prism has height 4 millimeters and width 5 millimeters.If the total surface area is 166 square millimeters, what is the length of the prism \n" ); document.write( "

Algebra.Com's Answer #85695 by bucky(2189) $\"\"$ $\"About$

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The rectangular prism has two ends that are each 4 mm by 5 mm. The product of 4 mm times 5 mm
\n" ); document.write( "is 20 sq mm and since there are two of these ends, the total surface area of the ends is 40 sq mm.
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\n" ); document.write( "This means that the remaining surface area is 166 sq mm minus 40 sq mm = 126 sq mm and this is
\n" ); document.write( "the surface area that is left for the sides. If L represents the length of the prism, then
\n" ); document.write( "there are two sides that each have a surface area of 4 mm times L and two sides that each have
\n" ); document.write( "a surface area of 5 mm times L. That means that the remaining surface area can be calculated from:
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\n" ); document.write( "2(4L + 5L) = 2(9L) = 18L
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\n" ); document.write( "So:
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\n" ); document.write( "18L = 126 sq mm
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\n" ); document.write( "Solve for L by dividing both sides by 18 and you get:
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\n" ); document.write( "L = 126/18 = 7 mm
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\n" ); document.write( "Hope this shows you a way through the problem. It probably would be a little more understandable
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