document.write( "Question 1145748: A man is four years older than his wife and 5 times than his son. When the son was born, the age of wife is six-seventh that of the husband’s age. Find the age of the wife. \n" ); document.write( "
Algebra.Com's Answer #767001 by Theo(13342)\"\" \"About 
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i get the following solution.\r
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\n" ); document.write( "\n" ); document.write( "the age of the man is 33.6
\n" ); document.write( "the age of the wife is 29.6
\n" ); document.write( "the age of the son is 5.6\r
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\n" ); document.write( "\n" ); document.write( "the man is 4 years older than his wife (33.6 - 29.6 = 4)
\n" ); document.write( "the man is 5 times older than his son ((33.6-5.6)/5.6 = 5)\r
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\n" ); document.write( "\n" ); document.write( "when the son was born, the wife was 6/7 * the age of the man.
\n" ); document.write( "29.6 - 5.6 = 24
\n" ); document.write( "33.6 - 5.6 = 28
\n" ); document.write( "24/28 = 6/7\r
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\n" ); document.write( "\n" ); document.write( "you said \"and 5 times than his son\"
\n" ); document.write( "i took that to mean \"5 times older than his son\"
\n" ); document.write( "if that's not what you meant, than you need to clarify what you meant.\r
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\n" ); document.write( "\n" ); document.write( "5 times older than his son means that that the father is 6 times as old as his son.\r
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\n" ); document.write( "\n" ); document.write( "if you meant \"5 times as old as his son\", then the solution winds up being the same, but with different numbers as shown below.\r
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\n" ); document.write( "\n" ); document.write( "the man is 35.
\n" ); document.write( "the woman is 31.
\n" ); document.write( "the son is 7 (5 * 7 = 35)\r
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\n" ); document.write( "\n" ); document.write( "7 years ago, the son was born.
\n" ); document.write( "the women was 31 - 7 = 24
\n" ); document.write( "the man was 35 - 7 = 28
\n" ); document.write( "24 / 28 = 6/7\r
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\n" ); document.write( "\n" ); document.write( "the method of solution, assuming the man was 5 times as old as his son, was as follows:\r
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\n" ); document.write( "\n" ); document.write( "let m = the age of the man
\n" ); document.write( "let w = the age of the woman
\n" ); document.write( "let s = the age of the son.\r
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\n" ); document.write( "\n" ); document.write( "you are given that:\r
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\n" ); document.write( "\n" ); document.write( "m = w + 4
\n" ); document.write( "m = 5 * s
\n" ); document.write( "since m = w + 4 and m = 5 * s, then you get w + 4 = 5 * s
\n" ); document.write( "solve for s to get s = (w + 4) / 5\r
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\n" ); document.write( "\n" ); document.write( "the son was born s years ago.
\n" ); document.write( "when the son was born, the woman was 6/7 * the man's age.
\n" ); document.write( "you get (w - s) = 6/7 * (m - s)
\n" ); document.write( "multiply both sides of this equation by 7/6 and you get:
\n" ); document.write( "7/6 * (w - s) = (m - s) which can also be shown as:
\n" ); document.write( "(m - s) = 7/6 * (w - s)
\n" ); document.write( "multiply both sides of this equation by 6 to get:
\n" ); document.write( "6 * (m - s) = 7 * (w - s)
\n" ); document.write( "simplify to get:
\n" ); document.write( "6m - 6s = 7w - 7s\r
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\n" ); document.write( "\n" ); document.write( "this last equation is used to solve the problem.
\n" ); document.write( "start with 6m - 6s = 7w - 7s
\n" ); document.write( "replace m with w + 4 and replace s with (w + 4) / 5 to get:
\n" ); document.write( "6 * (w + 4) - 6 * (w + 4) / 5) = 7 * w - 7 * (w + 4) / 5
\n" ); document.write( "multiply both sides of this equation by 5 to get:
\n" ); document.write( "30 * (w + 4) - 6 * (w + 4) = 35 * w - 7 * (w + 4)
\n" ); document.write( "simplify to get:
\n" ); document.write( "30 * w + 120 - 6 * w - 24 = 35 * w - 7 * w - 28
\n" ); document.write( "combine like terms to get:
\n" ); document.write( "24 * w + 96 = 28 * w - 28
\n" ); document.write( "subtract 24 * w from both sides and add 28 to both sides to get:
\n" ); document.write( "124 = 4 * w
\n" ); document.write( "solve for w to get:
\n" ); document.write( "w = 31\r
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\n" ); document.write( "\n" ); document.write( "since m = w + 4, the m = 35
\n" ); document.write( "since m = 5 * s, then s = 7\r
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\n" ); document.write( "\n" ); document.write( "you get:
\n" ); document.write( "m = 35
\n" ); document.write( "w = 31
\n" ); document.write( "s = 7\r
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\n" ); document.write( "\n" ); document.write( "the son was born 7 years ago.
\n" ); document.write( "the man was 28
\n" ); document.write( "the woman was 24
\n" ); document.write( "24/28 = 6/7\r
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\n" ); document.write( "\n" ); document.write( "your solution, assuming that the man is 5 times as old as his son, is that the wife is 31 years old.\r
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\n" ); document.write( "\n" ); document.write( "similar logic was applied if i assumed that the man was 6 times as old as his son.
\n" ); document.write( "in that case, w + 4 = 6s which makes s = (w + 4) / 6.\r
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\n" ); document.write( "\n" ); document.write( "assuming the man is 5 times as old as his son, rather than assuming the man is 5 times older than his son, gave me a cleaner answer.\r
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\n" ); document.write( "\n" ); document.write( "that's why i'm thinking you meant 5 times as old as his son, rather than 5 times older than his son.\r
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