Question 934474
{{{A=(2/3)J}}}
In twelve years,
{{{(A+12)+(J+12)=54}}}<--- This is where you had a mistake, the 12 should be  outside the parentheses
{{{(2/3)J+J+24=54}}}
{{{(2/3)J+(3/3)J=30}}}
{{{(5/3)J=30}}}
{{{J=90/5}}}
{{{J=18}}}
{{{A=(2/3)18}}}
{{{A=12}}}