document.write( "Question 198520: A rectangular flower bed 30 yards long by 20 yards wide has a walk of uniform width around it. If the area of the path is 1/4 that of the flower bed, find the width of the path. \n" ); document.write( "
Algebra.Com's Answer #149044 by nerdybill(7384)\"\" \"About 
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A rectangular flower bed 30 yards long by 20 yards wide has a walk of uniform width around it. If the area of the path is 1/4 that of the flower bed, find the width of the path.
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\n" ); document.write( "Let w = width of path
\n" ); document.write( "then
\n" ); document.write( "Area of flower bed = (30)(20) = 600 sq yards
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\n" ); document.write( "Area of flower bed and walk = (30+2w)(20+2w)
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\n" ); document.write( "Area of path = \"area of flower bed and walk\" - \"area of flower bed\"
\n" ); document.write( "Area of path = (30+2w)(20+2w) - 600
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\n" ); document.write( "(1/4)600 = (30+2w)(20+2w) - 600
\n" ); document.write( "150 = (30+2w)(20+2w) - 600
\n" ); document.write( "750 = (30+2w)(20+2w)
\n" ); document.write( "750 = 600+60w+40w+4w^2
\n" ); document.write( "750 = 4w^2+100w+600
\n" ); document.write( "0 = 4w^2+100w-150
\n" ); document.write( "0 = 2w^2+50w-75
\n" ); document.write( "Using the quadratic equation we get:
\n" ); document.write( "w = {1.42, -26.42}
\n" ); document.write( "Throw out the negative solution leaves us with:
\n" ); document.write( "w = 1.42 yards
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\n" ); document.write( "Details of quadratic to follow:
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Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation \"aw%5E2%2Bbw%2Bc=0\" (in our case \"2w%5E2%2B50w%2B-75+=+0\") has the following solutons:
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\n" ); document.write( " \"w%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca\"
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\n" ); document.write( " For these solutions to exist, the discriminant \"b%5E2-4ac\" should not be a negative number.
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\n" ); document.write( " First, we need to compute the discriminant \"b%5E2-4ac\": \"b%5E2-4ac=%2850%29%5E2-4%2A2%2A-75=3100\".
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\n" ); document.write( " Discriminant d=3100 is greater than zero. That means that there are two solutions: \"+x%5B12%5D+=+%28-50%2B-sqrt%28+3100+%29%29%2F2%5Ca\".
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\n" ); document.write( " \"w%5B1%5D+=+%28-%2850%29%2Bsqrt%28+3100+%29%29%2F2%5C2+=+1.41941090707505\"
\n" ); document.write( " \"w%5B2%5D+=+%28-%2850%29-sqrt%28+3100+%29%29%2F2%5C2+=+-26.4194109070751\"
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\n" ); document.write( " Quadratic expression \"2w%5E2%2B50w%2B-75\" can be factored:
\n" ); document.write( " \"2w%5E2%2B50w%2B-75+=+2%28w-1.41941090707505%29%2A%28w--26.4194109070751%29\"
\n" ); document.write( " Again, the answer is: 1.41941090707505, -26.4194109070751.\n" ); document.write( "Here's your graph:
\n" ); document.write( "\"graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+2%2Ax%5E2%2B50%2Ax%2B-75+%29\"
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