Question 640733
Let {{{ x }}} = Annie's age now
Just look at the part that says
"when Alma was as old as Annie is now"
That means that Alma was {{{ x }}} years old
The difference in their age will always be {{{ 36 - x }}}
That means that when Alma was {{{ x }}} years old,
Annie was {{{ x -( 36 - x ) = 2x - 36 }}}
It says that Alma is now twice that age, so
{{{ 36 = 2*( 2x - 36 ) }}}
{{{ 36 = 4x - 72 }}}
{{{ 4x = 108 }}}
{{{ x = 27 }}}
Annie is 27
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check:
When Alma was 27, that was 36 - 27 = 9 years
ago. Annie was 27 - 9 = 18
Alma is twice that age, or 2x18 - 36
OK