document.write( "Question 1067225: Two years ago, my age was four times that of my son. Eight years ago, my age was ten times that of my son. Find the age of my son now. \n" ); document.write( "
Algebra.Com's Answer #682411 by addingup(3677)\"\" \"About 
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f-4 = 4(s-4)
\n" ); document.write( "f-4 = 4s-16
\n" ); document.write( "f = 4s-12
\n" ); document.write( "4s-f = 12 (1)
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\n" ); document.write( "f-8 = 10(s-8)
\n" ); document.write( "f-8 = 10s-80
\n" ); document.write( "f = 10s-72
\n" ); document.write( "10s-f = 72 (2)
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\n" ); document.write( "multiply all terms in (1) times -1 and add to (2):
\n" ); document.write( "10s-f = 72
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\n" ); document.write( "-4s+f = -12
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\n" ); document.write( "6s+0 = 60
\n" ); document.write( "6s = 60
\n" ); document.write( "s = 10 the son is 10. And the father is:
\n" ); document.write( "f-4 = 4(10-4)
\n" ); document.write( "f-4 = 24
\n" ); document.write( "f = 28 the father is 28
\n" ); document.write( "Check: let's try the answers on the second equation
\n" ); document.write( "f-8 = 10(s-8)
\n" ); document.write( "28-8 = 10(10-8)
\n" ); document.write( "20 = 10(2) and 10*2 is 20, my answer is correct.\r
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