Question 846336
Let {{{ s }}} = her age now
{{{ s + 18 }}} = her age in 18 years
{{{ s - 9 }}} = her age 9 years ago
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given:
{{{ s + 18 = 2*( s - 9 ) }}}
{{{ s + 18 = 2s - 18 }}}
{{{ 18 = s - 18 }}}
{{{ s = 36 }}}
She is 36 now
check:
{{{ s + 18 = 2*( s - 9 ) }}}
{{{ 36 + 18 = 2*( 36 - 9 ) }}}
{{{ 54 = 2*27 }}}
{{{ 54 = 54 }}}
OK