Eureka is 9 years younger than Rex. In 3 years Rex will be twice as old as Eureka. How old are they now?

e = r-9

(r+3) = 2(e+3)

r+3 = 2(r-9+3)
r+3 = 2r-12
r = 15

Rex is 15
Eureka = 6

in three years, they will be 18 and 9