Answer:
30°
Step-by-step explanation:
From what I can picture, I suppose that ∠CDE is an exterior angle and is supplementary to ∠CDB.
Since ∠CDE is supplementary to ∠CDB, m∠CDB measures:
[tex]180-(7x-19)=199-7x[/tex]
And since the sum of interior angles of a triangle is 180°, we can write:
[tex](2x-1)+(199-7x)+(x+10)=180\\-4x+208=180\\-4x=-28\\x=7[/tex]
Substitute x back to ∠CDE:
[tex](7x-19)=(7(7)-19)\\=49-19\\=30[/tex]
