This is very simple.
ΔABE ~ ΔCDE
BE = x CE = y
x/18 = y/12
12x = 18y
y = 12x / 18
18 / 21-y = 12 / 19-x
18(19-x) = 12(21-y)
18(19-x) = 12(21- 12x/18)
x = 9 y = 6
I'll let you finish up your homework.
Thanks for answering Jugoslav.
However please don't state that a question is very simple because it sounds really insulting to the question asker.
In this case, I for one, do not think the question is as simple as you suggest.
Fuhsah,
Jugoslav has given you some insight which may be enough for you.
If it is not enough then please ask for more help.
State what you have done to try and help yourself though.