Hey there! I'll try to provide you with my best answer.
Answer: 7
In a straight line if you just mark the points, C, D, and E. It will be more easier for you to find out! So as said C to point E is 19 and point D to E is 12. In order to find point C to D, you can just subtract it. It is normally understandable that:
CE - DE = CD
So, place it in this way:
19 - 12 = 7
And there you go! We made it. Hope it helps!
