Question 732168
Let {{{ m }}} = Movie star's age now
Let {{{ c }}} = the child's age now
{{{ m - 5 }}} = Movie star's age 5 years ago
{{{ c - 5 }}} = child's age 5 years ago
given:
{{{ m = 5c }}}
{{{ m - 5 = 15*( c - 5 ) }}}
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By substitution:
{{{ 5c - 5 = 15*( c - 5 ) }}}
{{{ 5c - 5 = 15c - 75 }}}
{{{ 10c = 70 }}}
{{{ c = 7 }}}
and
{{{ m = 5c }}}
{{{ m = 5*7 }}}
{{{ m = 35 }}}
Her child is 7
check:
{{{ m - 5 = 15*( c - 5 ) }}}
{{{ 35 - 5 = 15*( 7 - 5 ) }}}
{{{ 30 = 15*2 }}}
{{{ 30 = 30 }}}
OK