Answer:
∠ABC = 34°
∠DBC = 44°
Step-by-step explanation:
The angle sum theorem tells you ...
(5x+4) +(5x-6) = 78
10x = 80 . . . . . . . . . . add 2 and simplify
x = 8
Then the two angles are ...
∠ABC = 5(8) -6 = 34°
∠DBC = 5(8) +4 = 44°
