document.write( "Question 178500: area of a rectangle= 220 square feet. find the diminensions of the figure.
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Algebra.Com's Answer #133435 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
Let Length=x and Width=x-9 Note: the order does not matter, but the length is usually the longer of the two.\r
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\n" ); document.write( "\n" ); document.write( "\"A=LW\" Start with the area of a rectangle formula\r
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\n" ); document.write( "\n" ); document.write( "\"220=x%28x-9%29\" Plug in \"A=220\", \"L=x\" and \"W=x-9\"\r
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\n" ); document.write( "\n" ); document.write( "\"220=x%5E2-9x\" Distribute\r
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\n" ); document.write( "\n" ); document.write( "\"0=x%5E2-9x-220\" Subtract 220 from both sides.\r
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\n" ); document.write( "\n" ); document.write( "Notice we have a quadratic equation in the form of \"ax%5E2%2Bbx%2Bc\" where \"a=1\", \"b=-9\", and \"c=-220\"\r
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\n" ); document.write( "\n" ); document.write( "Let's use the quadratic formula to solve for x\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-b+%2B-+sqrt%28+b%5E2-4ac+%29%29%2F%282a%29\" Start with the quadratic formula\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-%28-9%29+%2B-+sqrt%28+%28-9%29%5E2-4%281%29%28-220%29+%29%29%2F%282%281%29%29\" Plug in \"a=1\", \"b=-9\", and \"c=-220\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%289+%2B-+sqrt%28+%28-9%29%5E2-4%281%29%28-220%29+%29%29%2F%282%281%29%29\" Negate \"-9\" to get \"9\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%289+%2B-+sqrt%28+81-4%281%29%28-220%29+%29%29%2F%282%281%29%29\" Square \"-9\" to get \"81\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%289+%2B-+sqrt%28+81--880+%29%29%2F%282%281%29%29\" Multiply \"4%281%29%28-220%29\" to get \"-880\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%289+%2B-+sqrt%28+81%2B880+%29%29%2F%282%281%29%29\" Rewrite \"sqrt%2881--880%29\" as \"sqrt%2881%2B880%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%289+%2B-+sqrt%28+961+%29%29%2F%282%281%29%29\" Add \"81\" to \"880\" to get \"961\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%289+%2B-+sqrt%28+961+%29%29%2F%282%29\" Multiply \"2\" and \"1\" to get \"2\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%289+%2B-+31%29%2F%282%29\" Take the square root of \"961\" to get \"31\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%289+%2B+31%29%2F%282%29\" or \"x+=+%289+-+31%29%2F%282%29\" Break up the expression. \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%2840%29%2F%282%29\" or \"x+=++%28-22%29%2F%282%29\" Combine like terms. \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+20\" or \"x+=+-11\" Simplify. \r
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\n" ); document.write( "\n" ); document.write( "So the possible answers are \"x+=+20\" or \"x+=+-11\" \r
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\n" ); document.write( "\n" ); document.write( "However, since you can't have a negative length, this means that only solution is \"x=20\"\r
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\n" ); document.write( "\n" ); document.write( "So the length is \"L=x=20\" and the width is \"W=x-9=20-9=11\"\r
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\n" ); document.write( "\n" ); document.write( "Answer:\r
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\n" ); document.write( "\n" ); document.write( "So the length is 20 ft and the width is 11 ft
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