document.write( "Question 182199: Find the dimensions of a rectangle that has an area 48 m^2 and a diagonal of length 10 m. \n" ); document.write( "
Algebra.Com's Answer #136726 by Earlsdon(6294)\"\" \"About 
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Let x = the length of the rectangle and y = the width of the rectangle.
\n" ); document.write( "The area is x*y = 48 sq.m.
\n" ); document.write( "The diagonal is 10 m, so \"x%5E2%2By%5E2+=+10%5E2\" from the Pythagorean theorem.
\n" ); document.write( "So we have two equations:
\n" ); document.write( "1) \"x%2Ay+=+48\" Rewrite this equation as: \"x+=+48%2Fy\" and substitute into equation 2).
\n" ); document.write( "2) \"x%5E2%2By%5E2+=+100\"
\n" ); document.write( "2a) \"%2848%2Fy%29%5E2%2By%5E2+=+100\" Simplifying this, we get:
\n" ); document.write( "2a) \"2304%2Fy%5E2+%2B+y%5E2+=+100\"
\n" ); document.write( "2a) \"%282304+%2B+y%5E4%29%2Fy%5E2+=+100\" Multiply both sides by \"y%5E2\"
\n" ); document.write( "2a) \"2304+%2B+y%5E4+=+100y%5E2\" Rearrange this into standard \"quadratic\" form.
\n" ); document.write( "\"y%5E4-100y%5E2%2B2034+=+0\" Solve by factoring, noting that \"y%5E4+=+%28y%5E2%29%5E2\"
\n" ); document.write( "\"%28y%5E2%29%5E2+-+100%28y%5E2%29%2B2304+=+0\"
\n" ); document.write( "\"%28%28y%5E2%29-64%29%28%28y%5E2%29-36%29+=+0\" Applying the zero product rule, we get:
\n" ); document.write( "\"y%5E2-64+=+0\" or \"y%5E2-36+=+0\" Factoring the left sides, we get:
\n" ); document.write( "\"%28y%2B8%29%28y-8%29+=+0\" or \"%28y%2B6%29%28y-6%29+=+0\" From which we get:
\n" ); document.write( "\"y+=+-8\"
\n" ); document.write( "\"y+=+8\"
\n" ); document.write( "\"y+=+-6\"
\n" ); document.write( "\"y+=+6\"
\n" ); document.write( "Discard the negative solutions as the lengths of the rectangle sides can only be positive.
\n" ); document.write( "So we have:
\n" ); document.write( "y = 6 or 8 and x = 8 or 6
\n" ); document.write( "The dimensions of the rectangle would be:
\n" ); document.write( "Length = 8m and width = 6m
\n" ); document.write( "Please note that while we solved only for y, the x-value is obtained by substituting y = 8 into eqation 1):
\n" ); document.write( "\"x%2Ay+=+48\" Substitute \"y+=+8\"
\n" ); document.write( "\"x%2A%288%29+=+48\" Dividing both sides by 8.
\n" ); document.write( "\"x+=+6\"
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