<PRE><B>Question 978635</B>
Hi there,
A is five times older than B
A = 5B
After 12 years A would be twice as old as B 
A + 12 = 2(B + 12)
Replace A with 5B from first equation
5B + 12 = 2(B + 12)
Multiply out
5B + 12 = 2B + 24
Collect like terms
5B - 2B = 24 - 12
3B = 12
B = 4
A is 20 yrs old
B is 4 yrs old
Hope this helps:-)</PRE>