Question 1100456
Third grade math???


Marie and Sarah (her sister?)


Sarah is 8 and if Marie is 10 years older, then Marie NOW is 18.



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How many years ago was Marie twice as old as Sarah was then? 
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x years ago.

{{{highlight_green(18-x=2(8-x))}}}


{{{18-x=16-2x}}}
{{{2-x=-2x}}}
{{{-2x+x=2}}}
{{{-x=2}}}
{{{highlight(x=-2)}}}-----------meaning, not two years ago, but two years FROM NOW, IN THE FUTURE.