I'm going to assume that you want to find Their ages....
Judi's age + Baz's age +Calebs age =64
Lets say Judi's age = j, Baz's age= B, Calebs age= c
J= 9+B, B= 2c, C= just c
So, J = 9+2c, B= 2c, C= C
Plug it in, and add like terms
9+2c+2c+c -----> 5c +9
5c+9=64, (isolate c)
5c+9-9 = 64-9 -----> 5c = 55 -----> c=11
Then plug calebs age everywhere needed.
Calebs age= 11, Baz's age= 22 Judi's age = 31.
11+22+31 = 64