Some one explain this

Answer:
13
Step-by-step explanation:
The triangles ABC and DEC are the exact same.
That also means that angle b in the same as angle E
You can then do: 3x=6x-39 (because they are the same)
then simplify:
39=3x
x=13
hope this helped! ask questions in the comments if you still don't know.
Answer:
Make x alone
Subtract 3x on both sides
3x - 3x = 0
6x - 3x = 3x
0 = 3x - 39
Divide 39 by 3
39 / 3 = 13
13 is the answer because it makes the equation equal
Hope this helps
Step-by-step explanation: