document.write( "Question 979578: Mr. Smith is 5 times as old as hiandsons gr. Four years ago, he was 7 times as old as his grandson. How old is he? \n" ); document.write( "

Algebra.Com's Answer #600892 by Cromlix(4381) $\"\"$ $\"About$

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Hi there,
\n" ); document.write( "Mr. Smith is 5 times as old as his grandson.
\n" ); document.write( "S = 5G
\n" ); document.write( "........
\n" ); document.write( "Four years ago, he was 7 times as old as his grandson.
\n" ); document.write( "S - 4 = 7(G - 4)
\n" ); document.write( "Multiply out
\n" ); document.write( "S - 4 = 7G - 28
\n" ); document.write( "Replace 'S' with '5G'
\n" ); document.write( "from top equation
\n" ); document.write( "5G - 4 = 7G - 28
\n" ); document.write( "collect like terms
\n" ); document.write( "5G - 7G = - 28 + 4
\n" ); document.write( "-2G = -24
\n" ); document.write( "Multiply both sides by -1
\n" ); document.write( "2G = 24
\n" ); document.write( "G = 12
\n" ); document.write( "Mr Smith is (12 x 5) 60 years old
\n" ); document.write( "Grandson is 12 years old.
\n" ); document.write( "Hope this helps:-)
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