document.write( "Question 59822: can you please help me with this word problem. thank you very much\r
\n" ); document.write( "\n" ); document.write( "112. Swimming pool design. An architect has a designed a motel pool with in a rectangular area the is fenced on three sides. If she uses 60 yards of fencing to enclose as area of 352 square yards, then what are the dimensions for L and W? Assume L is greater than W
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Algebra.Com's Answer #41071 by joyofmath(189)\"\" \"About 
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Let the width of the pool = W and the length of the pool = L. We are told that the length is greater than W so \"L+%3E+W\".\r
\n" ); document.write( "\n" ); document.write( "Assume the three sides that are fenced in are the two widths and one length, and that's with 60 yards of fencing. Thus, \r
\n" ); document.write( "\n" ); document.write( "(1) \"2W%2BL+=+60\"\r
\n" ); document.write( "\n" ); document.write( "We also know that the area of the pool = 352. So, \r
\n" ); document.write( "\n" ); document.write( "(2) \"LW+=+352\"\r
\n" ); document.write( "\n" ); document.write( "Subtract \"2W\" from both sides of (1) to get \"L+=+60-2W\"\r
\n" ); document.write( "\n" ); document.write( "Replace L with \"60-2W\" in (2) to get \r
\n" ); document.write( "\n" ); document.write( "(3) \"%2860-2W%29W+=+352\"\r
\n" ); document.write( "\n" ); document.write( "Now, multiply \"60-2W\" by W and we get \"60W-2W%5E2\".
\n" ); document.write( "So, (3) becomes \"60W-2W%5E2+=+352\" or \r
\n" ); document.write( "\n" ); document.write( "(4) \"60W-2W%5E2-352+=+0\"\r
\n" ); document.write( "\n" ); document.write( "This is a quadratic equation which can also be written as \"-2W%5E2%2B60W-352+=+0\". \r
\n" ); document.write( "\n" ); document.write( "We divide both sides by 2 and get \"-W%5E2%2B30W-176+=+0\".\r
\n" ); document.write( "\n" ); document.write( "The coefficients of this quadratic equation are -1, 30, and -176.\r
\n" ); document.write( "\n" ); document.write( "Remember the quadratic equation, solving for w: \"W+=+%28-b+%2B-+sqrt%28b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+\"\r
\n" ); document.write( "\n" ); document.write( "Replace a, b, and c with -1, 30, and -176 respectively and you get\r
\n" ); document.write( "\n" ); document.write( "\"W+=+%28-%2830%29+%2B-+sqrt%2830%5E2+-+4%2A%28-1%29%2A%28-176%29%29%29+%2F+%282%2A%28-1%29%29\"\r
\n" ); document.write( "\n" ); document.write( "Multiply things out and you get\r
\n" ); document.write( "\n" ); document.write( "\"W+=+%28-30+%2B-+sqrt%28900+-+704%29%29+%2F+-2\" or\r
\n" ); document.write( "\n" ); document.write( "\"W+=+%28-30+%2B-+sqrt%28196%29%29+%2F+-2\"\r
\n" ); document.write( "\n" ); document.write( "\"sqrt%28196%29+=+14\" so \"W+=+%28-30+%2B-+14%29+%2F+-2\"\r
\n" ); document.write( "\n" ); document.write( "So, W can equal \"%28-30+%2B+14%29+%2F+-2\" which = 8
\n" ); document.write( "or W can equal \"%28-30+-+14+%29+%2F+-2\" which = 22\r
\n" ); document.write( "\n" ); document.write( "From (1) we know that \"2W%2BL+=+60\". If W = 8 then \"2%2AW%2BL+=+60\" or \"16%2BL+=+60\" so \"L+=+44\".\r
\n" ); document.write( "\n" ); document.write( "If W = 22 then \"2%2AW%2BL+=+60\" or \"2%2A22+%2B+L+=+60\" or \"44%2BL+=+60\" so \"L=16\". But, L must be > W and 16 is not > 22 so W = 22 is not a solution.\r
\n" ); document.write( "\n" ); document.write( "So, L = 44. and from (1) we know that \"2W%2BL+=+60\" so \"2W%2B44+=+60\" so \"2W+=+16\" and \"W+=+8\".\r
\n" ); document.write( "\n" ); document.write( "To verify our answer, that \"L+=+44\" and \"W+=+8\" we plug these values into (1) and (2):\r
\n" ); document.write( "\n" ); document.write( "\"2W%2BL+=+60\" so \"2%2A8+%2B+44\" should = 60 and it does.
\n" ); document.write( "\"LW+=+352\" so \"44%2A8\" should = 352 and it does.
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