document.write( "Question 509236: The length of a rectangle is five times its width.
\n" ); document.write( "If the area of the rectangle is 320cm^2 , find its perimeter
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Algebra.Com's Answer #341349 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
The formula for perimeter is:
\n" ); document.write( " $\"+P+=+2W+%2B+2L+\"$
\n" ); document.write( "The formula for area is:
\n" ); document.write( " $\"+A+=+L%2AW+\"$
\n" ); document.write( "given:
\n" ); document.write( " $\"+A+=+320+\"$ cm2
\n" ); document.write( "(1) $\"+L+=+5W+\"$
\n" ); document.write( "----------
\n" ); document.write( "(2) $\"+320+=+L%2AW+\"$
\n" ); document.write( "(2) $\"+L+=+320%2FW+\"$
\n" ); document.write( "Substitute (2) into (1)
\n" ); document.write( " $\"+320%2FW+=+5W+\"$
\n" ); document.write( " $\"+320+=+5W%5E2+\"$
\n" ); document.write( " $\"+W%5E2+=+64+\"$
\n" ); document.write( " $\"+W+=+8+\"$
\n" ); document.write( "and, since
\n" ); document.write( " $\"+L+=+5W+\"$
\n" ); document.write( " $\"+L+=+40+\"$
\n" ); document.write( "The length is 40 cm and the width is 8 cm
\n" ); document.write( "so, the perimeter is
\n" ); document.write( " $\"+P+=+2W+%2B+2L+\"$
\n" ); document.write( " $\"+P+=+2%2A8+%2B+2%2A40+\"$
\n" ); document.write( " $\"+P+=+16+%2B+80+\"$
\n" ); document.write( " $\"+P+=+96+\"$ cm \n" ); document.write( "

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