Question 53036
jim is now three times as old as kathy.
 in equation form: j = 3k
:
Four years ago, jim was seven times as old as kathy then.
   [J - 4] = 7[k - 4]
Substitute 3k for J, solve for k
   3k - 4 = 7[k - 4]
   3k - 4 = 7k - 28
  -4 + 28 = 7k - 3k
       24 = 4k
        k = 24/4
        k = 6 years old
:
 J = 3(6) = 18 years old
:
Check: 4 years ago, J = 14 and K was 2 years old; J was 7 times K's age