Question 864388
Let {{{ k }}} = her age now
{{{ k + 9 }}} = her age in 9 years
{{{ k - 7 }}} = her age 7 years ago
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{{{ k + 9 = 3*( k - 7 ) }}}
{{{ k + 9 = 3k - 21 }}}
{{{ 2k = 30 }}}
{{{ k = 15 }}}
Her present age is 15
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check:
{{{ k + 9 = 3*( k - 7 ) }}}
{{{ 15 + 9 = 3*( 15 - 7 ) }}}
{{{ 24 = 3*8 }}}
{{{ 24 = 24 }}}
OK