document.write( "Question 1199026: Four years ago,a mother was 4 times as old as her son.In 4 years time, the sum of their ages will be 56years .Find the age of the mother when the son was born \n" ); document.write( "
Algebra.Com's Answer #832709 by Theo(13342)\"\" \"About 
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x = the mother's age today.
\n" ); document.write( "y = the son's age today.\r
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\n" ); document.write( "\n" ); document.write( "4 years ago, the mother was 4 times as old as her son.
\n" ); document.write( "the equation for that is:
\n" ); document.write( "(x - 4) = 4 * (y -4)
\n" ); document.write( "simplify to get:
\n" ); document.write( "x - 4 = 4 * y - 16
\n" ); document.write( "solve for x to get:
\n" ); document.write( "x = 4 * y - 12\r
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\n" ); document.write( "\n" ); document.write( "in 4 years time, the sum of their ages will be 56.
\n" ); document.write( "the equation for that is:
\n" ); document.write( "x + 4 + y + 4 = 56
\n" ); document.write( "combine like terms to get:
\n" ); document.write( "x + y + 8 = 56
\n" ); document.write( "solve for x + y to get:
\n" ); document.write( "x + y = 48\r
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\n" ); document.write( "\n" ); document.write( "replace x in the second equation with 4 * y - 12 from the first equation to get:
\n" ); document.write( "4 * y - 12 + y = 48
\n" ); document.write( "combine like terms and add 12 to both sides of the equation to get:
\n" ); document.write( "5 * y = 60
\n" ); document.write( "solve for y to get:
\n" ); document.write( "y = 12\r
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\n" ); document.write( "\n" ); document.write( "since x + y = 48, then x = 36.
\n" ); document.write( "the mother's age is currently 36
\n" ); document.write( "the son's age is currently 12\r
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\n" ); document.write( "\n" ); document.write( "4 years ago, the mother was 32 and the son was 8.
\n" ); document.write( "32 is 4 * 8.
\n" ); document.write( "in 4 years time, the mother will be 40 and the son will be 16.
\n" ); document.write( "40 + 16 = 56.
\n" ); document.write( "the requirements of the problem are satisfied when the mother's current age is 36 and the son's current age is 12.\r
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\n" ); document.write( "\n" ); document.write( "the son was born 12 years ago.
\n" ); document.write( "12 years ago, the mother was 24.
\n" ); document.write( "the mother was 24 years old when the son was born.
\n" ); document.write( "that's your solution.\r
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