document.write( "Question 214079: The perimeter of a rectangle is 35 cm. Express the area, A, of the rectangle as a function of its width, x. \n" ); document.write( "

Algebra.Com's Answer #161688 by josmiceli(19441) $\"\"$ $\"About$

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$\"A+=+x%2Ay\"$ cm2
\n" ); document.write( " $\"y+=+A%2Fx\"$
\n" ); document.write( " $\"P+=+35\"$ cm
\n" ); document.write( " $\"P+=+2x+%2B+2y\"$
\n" ); document.write( " $\"2x+%2B+2y+=+35\"$
\n" ); document.write( " $\"2y+=+35+-+2x\"$
\n" ); document.write( " $\"2%2A%28A%2Fx%29+=+35+-+2x\"$
\n" ); document.write( " $\"2A+=+35x+-+2x%5E2\"$
\n" ); document.write( " $\"A+=+-x%5E2+%2B+17.5x\"$ answer
\n" ); document.write( "check answer:
\n" ); document.write( "Suppose $\"x+=+12\"$ cm
\n" ); document.write( " $\"A+=+-144+%2B+17.5%2A12\"$
\n" ); document.write( " $\"A+=+-144+%2B+210\"$
\n" ); document.write( " $\"A+=+66\"$ cm2
\n" ); document.write( " $\"P+=+2x+%2B+2y\"$
\n" ); document.write( " $\"35+=+2%2A12+%2B+2y\"$
\n" ); document.write( " $\"2y+=+35+-+24\"$
\n" ); document.write( " $\"2y+=+11\"$
\n" ); document.write( " $\"y+=+5.5\"$
\n" ); document.write( " $\"A+=+xy\"$
\n" ); document.write( " $\"A+=+12%2A5.5\"$
\n" ); document.write( " $\"A+=+66\"$ cm2
\n" ); document.write( "OK \n" ); document.write( "

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