document.write( "Question 936218: mr.jackson has a rectangular shaped garden where the length was 4 less than twice the width. if the area of the garden is 420 square feet, find the dimensions of the garden to the nearest hundredth. \n" ); document.write( "
Algebra.Com's Answer #569657 by srinivas.g(540)\"\" \"About 
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let width be x feet
\n" ); document.write( " length was 4 less than twice the width
\n" ); document.write( " length = 2*x-4
\n" ); document.write( " area = width x length
\n" ); document.write( " 420 = x* (2x-4)
\n" ); document.write( " 420 = x*2x-x*4
\n" ); document.write( " \"+420+=2x%5E2-4x\"
\n" ); document.write( " move 420 to the right
\n" ); document.write( " \"0+=+2x%5E2-4x-420\"
\n" ); document.write( "\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "
Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation \"ax%5E2%2Bbx%2Bc=0\" (in our case \"2x%5E2%2B-4x%2B-420+=+0\") has the following solutons:
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\n" ); document.write( " \"x%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca\"
\n" ); document.write( "
\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=%28-4%29%5E2-4%2A2%2A-420=3376\".
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\n" ); document.write( " Discriminant d=3376 is greater than zero. That means that there are two solutions: \"+x%5B12%5D+=+%28--4%2B-sqrt%28+3376+%29%29%2F2%5Ca\".
\n" ); document.write( "
\n" ); document.write( " \"x%5B1%5D+=+%28-%28-4%29%2Bsqrt%28+3376+%29%29%2F2%5C2+=+15.5258390463339\"
\n" ); document.write( " \"x%5B2%5D+=+%28-%28-4%29-sqrt%28+3376+%29%29%2F2%5C2+=+-13.5258390463339\"
\n" ); document.write( "
\n" ); document.write( " Quadratic expression \"2x%5E2%2B-4x%2B-420\" can be factored:
\n" ); document.write( " \"2x%5E2%2B-4x%2B-420+=+2%28x-15.5258390463339%29%2A%28x--13.5258390463339%29\"
\n" ); document.write( " Again, the answer is: 15.5258390463339, -13.5258390463339.\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%2B-4%2Ax%2B-420+%29\"

\n" ); document.write( "\n" ); document.write( " x= 15.53 , -13.53
\n" ); document.write( " but x cannot be negative
\n" ); document.write( " hence width (w) = 15.53 feet
\n" ); document.write( " length (l) = 2*15.53-4
\n" ); document.write( " = 31.06-4
\n" ); document.write( " = 27.06 feet
\n" ); document.write( "length = 27.06 feet & width = 15.53 feet
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