document.write( "Question 216705: a father seven years ago was eleven times as old as his daughter. now he is four times as old as she is. how old is he? the answer is 40 i just don't know how to acquire it. \n" ); document.write( "

Algebra.Com's Answer #163603 by ankor@dixie-net.com(22740) $\"\"$ $\"About$

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Let f = father's present age
\n" ); document.write( "let d = daughter's present age
\n" ); document.write( ":
\n" ); document.write( "Write an equation for each statement:
\n" ); document.write( ":
\n" ); document.write( "\"father seven years ago was eleven times as old as his daughter.\"
\n" ); document.write( "f - 7 = 11(d - 7)
\n" ); document.write( "f - 7 = 11d - 77
\n" ); document.write( "f = 11d - 77 + 7
\n" ); document.write( "f = 11d - 70
\n" ); document.write( ":
\n" ); document.write( "\"now he is four times as old as she is.\"
\n" ); document.write( "f = 4d
\n" ); document.write( ":
\n" ); document.write( " how old is he?
\n" ); document.write( ";
\n" ); document.write( "Replace f with 4d in the equation: f = 11d - 70
\n" ); document.write( "4d = 11d - 70
\n" ); document.write( "70 = 11d - 4d
\n" ); document.write( "70 = 7d
\n" ); document.write( "d = 10 yrs is daughter
\n" ); document.write( "then
\n" ); document.write( "4(10) = 40 is father \n" ); document.write( "

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