Answer:
x = 13.5
BC = 30
Explanation:
BC is double the length of DE. And we know that DE is equal to 15. So 15 x 2 is 30.
Now to find x. We know that our answer has to add up to 30. So we first subtract 3 from 30 to get 27. Then divide 27 by 2 to get what x is equal to. x = 13.5