Question 1094935
<br>Let x be one of their current ages; suppose it is Sarah's.  Then, since the sum of their ages is 42, Greg's current age is 42-x.<br>
We are told that Greg's age 20 years from now will be twice what Sarah's age was 14 years ago.<br>
Greg's age 20 years from now will be (42-x)+20 = 62-x; Sarah's age 14 years ago was x-14. So
{{{62-x = 2(x-14)}}}
{{{62-x = 2x-28}}}
{{{90 = 3x}}}
{{{x = 30}}}<br>
Sarah's current age is 30; Greg's is 42-30 = 12