document.write( "Question 503181: A rectangle has a perimeter of 600 in. Express the area, A, of the rectangle as a function of the length of one of its sides x. \n" ); document.write( "

Algebra.Com's Answer #339138 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
If one side is $\"x\"$ , the opposite side is also $\"x\"$
\n" ); document.write( "Their sum is $\"2x\"$
\n" ); document.write( "Call the other 2 sides $\"y\"$
\n" ); document.write( "Call the perimeter $\"P\"$
\n" ); document.write( " $\"+P+=+2x+%2B+2y+\"$
\n" ); document.write( "solve for $\"y\"$
\n" ); document.write( " $\"+2y+=+P+-+2x+\"$
\n" ); document.write( " $\"+y+=+%28P%2F2%29+-+x+\"$
\n" ); document.write( "And, since $\"+P+=+600+\"$ ,
\n" ); document.write( " $\"+y+=+300+-+x+\"$
\n" ); document.write( "The area os the rectangle is $\"+A+=+x%2Ay+\"$
\n" ); document.write( " $\"+A+=+x%2A%28+300+-+x+%29+\"$
\n" ); document.write( " $\"+A+=+300x+-+x%5E2+\"$
\n" ); document.write( "Here's a plot of area and x:
\n" ); document.write( " $\"+graph%28+400%2C+400%2C+-40%2C+330%2C+-1000%2C+25000+%2C+300x+-+x%5E2%29+\"$ \n" ); document.write( "

\n" );