document.write( "Question 165093: A 10m by 34m garden is surrounded by a walkway of uniform width (call it \"x\"). The total area of the garden and walkway is 640 square meters. what is the width of the walkway? \n" ); document.write( "
Algebra.Com's Answer #121684 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
Let x = width of the path\r
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\n" ); document.write( "\n" ); document.write( "With these type of problems, it helps to draw a picture. So draw two rectangles, one inside of the other, and label the inside rectangle's dimensions:\r
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\n" ); document.write( "\n" ); document.write( "Now the label the width of the path \"x\" (denoted in red)\r
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\n" ); document.write( "\n" ); document.write( "\"Photobucket\r
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\n" ); document.write( "\n" ); document.write( "Since there are 2 \"x\" lengths per side, this means that you need to add \"2x\" to both the length and width of the inner rectangle to get the length and width of the outer rectangle. If this makes no sense at all, here's a visual:\r
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\n" ); document.write( "\n" ); document.write( "So the length and width of the outer rectangle is \"34%2B2x\" and \"10%2B2x\" respectively. This means that for the outer rectangle \"A=640\" (the given area of both the walkway and the garden), \"L=34%2B2x\" and \"W=10%2B2x\"\r
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\n" ); document.write( "\n" ); document.write( "Remember, the area of any rectangle is \"A=LW\"\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( "\"640=%2834%2B2x%29%2810%2B2x%29\" Plug in \"A=640\", \"L=34%2B2x\" and \"W=10%2B2x\"\r
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\n" ); document.write( "\n" ); document.write( "\"640=340%2B68x%2B20x%2B4x%5E2\" FOIL\r
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\n" ); document.write( "\n" ); document.write( "\"0=340%2B68x%2B20x%2B4x%5E2-640\" Subtract 640 from both sides.\r
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\n" ); document.write( "\n" ); document.write( "\"0=4x%5E2%2B88x-300\" Combine like terms.\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=4\", \"b=88\", and \"c=-300\"\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-%2888%29+%2B-+sqrt%28+%2888%29%5E2-4%284%29%28-300%29+%29%29%2F%282%284%29%29\" Plug in \"a=4\", \"b=88\", and \"c=-300\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-88+%2B-+sqrt%28+7744-4%284%29%28-300%29+%29%29%2F%282%284%29%29\" Square \"88\" to get \"7744\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-88+%2B-+sqrt%28+7744--4800+%29%29%2F%282%284%29%29\" Multiply \"4%284%29%28-300%29\" to get \"-4800\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-88+%2B-+sqrt%28+7744%2B4800+%29%29%2F%282%284%29%29\" Rewrite \"sqrt%287744--4800%29\" as \"sqrt%287744%2B4800%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-88+%2B-+sqrt%28+12544+%29%29%2F%282%284%29%29\" Add \"7744\" to \"4800\" to get \"12544\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-88+%2B-+sqrt%28+12544+%29%29%2F%288%29\" Multiply \"2\" and \"4\" to get \"8\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-88+%2B-+112%29%2F%288%29\" Take the square root of \"12544\" to get \"112\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-88+%2B+112%29%2F%288%29\" or \"x+=+%28-88+-+112%29%2F%288%29\" Break up the expression. \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%2824%29%2F%288%29\" or \"x+=++%28-200%29%2F%288%29\" Combine like terms. \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+3\" or \"x+=+-25\" Simplify. \r
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\n" ); document.write( "\n" ); document.write( "So the possible answers are \"x+=+3\" or \"x+=+-25\" \r
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\n" ); document.write( "\n" ); document.write( "However, since a negative width is not possible, this means that \"x+=+-25\" is NOT a solution.\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 solution is \"x+=+3\" which means that the width of the path is 3 meters.
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