(2x+4) +(3x-1) +(x+1)=34
6x+4=34
x=5
AB=14, BC=14, AC=6
It is 838
Step-by-step explanation:
The result follows directly from properties of modular arithmetic:

That is,

means we can write
for some integer
. Then

and taken mod 12, the first term goes away, so

etc