document.write( "Question 1185597: A rectangle measures 4 ft by 10 ft. We’d like to double the area by extending each side by the same amount. How much do we need to extend each side? Find the answer by writing and solving a quadratic equation.
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Algebra.Com's Answer #816420 by josgarithmetic(39617) $\"\"$ $\"About$

You can put this solution on YOUR website!
From $\"4%2A10\"$ $\"ft%5E2\"$ to $\"%284%2Bx%29%2810%2Bx%29=2%2A4%2A10\"$ \r
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\n" ); document.write( "\n" ); document.write( " $\"4%2A10%2B10x%2B4x%2Bx%5E2=2%2A4%2A10\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"14x%2Bx%5E2=4%2A10\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"x%5E2%2B14x=40\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"x%5E2%2B14x-40=0\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"x=%28-14%2B-+sqrt%28196%2B4%2A40%29%29%2F2\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"x=%28-14%2B-+sqrt%28356%29%29%2F2\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"x=-7%2Bsqrt%2889%29\"$ $\"about\"$ $\"2.434\"$ \r
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\n" ); document.write( "check: $\"%284%2B2.434%29%2810%2B2.434%29=6.434%2A12.434=80.00\"$
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